Year 1 Biochemistry Cellular Composition (BCC) Notes PDF

#separator:tab #html:true What does Gibbs free energy tell us? Tells us if a reaction will occur spontaneously  - free energy decreases in spontaneous reactions What does it mean if ∆G > 0? Endergonic (non-spontaneous) reaction reaction very unlikely to occur at that temperature What does it mean if ∆G = 0? Reaction occurs in equilibriumit is used to find out the minimum temperature a reaction can take place in What does it mean if ∆G < 0? Exergonic (spontaneous) reactionThe reaction will always occur at that temperature Gibbs free energy equation:When ∆G = 0 ∆G = ∆H - T∆S∆H = T∆S Explain the trend in disorder in relation to ∆G: As entropy increases - meaning disorder increases therefore lower ∆G (as when ∆G < 0 then the reaction is more likely to occur spontaneously) Describe how water molecules arrange themselves around a protein using hydrophobic interactions: "Water moelcuels close to te surface of hydrophbic proteins have few opportuniteis to form hydrogen bonds between one anotherConsequently, many water molecuels form ordered ice-like ""shells"" around the protein" What is the entropy of the hydrophobic interactions in a protein? How does this effect the reactions regarding to expenses? "The system has a low ∆S thus ∆G is hightherefore Ordered shells have an energetic cost" What can we do to increase entropy without increasing temperature or energy and being more cost effective? If the hydrophobic SA is minimised, the n.o ordered water molecules is reduced.This increases ∆S thus reducing ∆G How deos the hydrophobic effect affect/dominate protein structure? The hydrophobic effect drives hydrophobic molecules together.it is a dominant force in protein folding What is the equation for the dissociation of water? "H2O ⇌ H+ (or H3O+) + OH- " What is the ratio of ions in pure/neutral water? 1:1[H+] = [OH-] What is pH? pH = -log[H+] What is the equation for the equilibrium dissociation constant for water (K)? [H+][OH-] / [H2O] What is/meaning of the Ka for water? the dissociation constant for pure water at 25ºC What is Kw? "the ""ion product"" constant at 25ºCKw for water = 10-14 [H+][OH-] = 10-14 is valid for ANY aq. solution" What is Ka? the equilibrium constant, is a measure of the strangth of an acid or base Equation for Ka: Ka = [A-][H+] / [HA] Equation for pKa involving Ka: pKa = -logKa ORKa = 10-pKa What is the Henderson-Hasslebalch Equation? pH = pKa + log[A-]/[HA] What is the Le Chantelier's Principle? If a dynamic equilibrium is disturbed by changing the conditions, the postion of equilibrium moves to counteract the change What are buffers? they are weak acids/bases that dissociate or associate to realease or absorb pritons, thus resisting/preventing changes in pH Describe how buffers in the blood work: "Bicarbonate ions (HCO3-) is the major buffer system in the plasma and interstitial fluidIn tissues: CO2 + H2O ⇌ H2CO3 (carbonic acid)This immediately dissociates and ionises: H2CO3 ⇌ H+ + HCO3- (bicarbonate)THUS OVERALL:CO2 + H2O ⇌ H+ + HCO3-" Describe/explain how amino acids can act as buffers: "Naturally, amino acids are present as zwitter ions" What are the properties of water due to? (3) Its SizeIts ShapeIts Polarity What does the hydrophobic effect explain to us? why non-polar molelcuels are forced together in aqueous solution What do buffers prevent from happening? Prevent changes in pH at around their pKa Describe the properties of water: (6) High specific heat capacityAdhesion and cohesion (high surface tension)High latent heat of vaporisationExcellent solvent propertiesLower density in solid form than liquid formActs as a transport medium and  a medium for reactions What is the bond angle of water? 104.5º What does it mean when a molecule is polar? when 1 end of the moelecule is different to the other (1 is delta -ive and 1 is delta +ive) - due to separation of electrical charge (due to the different electronegativity levels). Why does oxygen bind to 2 hydrogen moelcules in water? as it is energetically favourable for O to do so How do you get from kCal --- kJ? ÷4.2 In which numbers are covalent bond energies usually in? In the 100s Describe the trend in bond energies going from covalent ---> H-bond ---> hydrophobic interactions --- Van der Waals: Down this series bond energies decrease as the intermolecular forces are weaker What is the van der waals radius? the radium of the whole atom/moelcule How much is 1 Ångström in metres? 1 x 10-10 What is a hydrogen bond? when a hydrogen atom is shared between 2 electronegative atoms (e.g. O or N).Elctrostatic, weak Are hydrogen bonds strong? They are weak individually but very strong all together How do you draw hydrogen bonds? 180º and vertical lines How far are H-bonds? They are 3Å apart Why is water such a good solvent? due to H-bondingmany molecules/substances can dissolve within water What happen to polar molecules in water? they dissolve in water as they can form H-bonds with water What happens to ionic moelcules in water? They dissociate and are surrounded (hydrated) by water forming HYDRATION SHELLS What happen to non-polar molecules in water? They repel water as they don't have similar bond energies  What does it mean when a reaction occurs spontaneously? that the reaction occurs without us putting energy into it what does it mean when a reaction is endergonic (non-spontaneous)? it requires an input of energy for the reaction to occur What happens to ∆G when we increase entropy (∆S)? Why? ∆G decreases this is as there is increased disorder therefore increased sponteneoty therefore a more spontaneous reaction What is the hydrophobic effect? Where non-polar molecules cluster together (decrease SA) in water to minimise the ordered water molecules, increasing entropy (∆S) and lowering ∆Git is the dominant force in protein foldingiot eplains why non-polar molecules are FORCED TOGETHER in aqueous solutions Why is change of entropy the most important driving factor in biological interaction? Due to H-bonding of H2O.proteins have a specific shape as they are dissolved in water What is another unit for M? molL-1 What is the Kw of pure water? 1 x 10-14 What is a STRONG acid? an acid that fully dissociates when in solution What is a WEAK acid? an acid that partially dissociates in solution (forms an ionic salt) Explain the relationship between acid strength and the Ka value: the weajer the acid, the lower the Ka as it takes more energy to stabilise the weak acid to form the salt (to ionise it) When does a buffer work best? at around its pKa (+ or - 1 unit from pKa) Meaning of interstitial fluid: fluid in between cells Describe the overall buffer reaction with HCO3-: describe how you got to this: "In the tissues:      CO2 + H2O ⇌ H2CO3 Carbonic acid immadiates ionises/dissociates:       H2CO3 ⇌ H+ + HCO3- OVERALLCO2 + H2O + H2CO3 ⇌ H2CO3 + H+ + HCO3- Cancel the yellows as they cancel outthereforeCO2 + H2O ⇌ H+ HCO3-" Why can amino acid buffer at 2 different pKa? as they have 2 sides that can buffer (amino group and acid group) at lower pH and higher pH What is mean by the central dogma? "DNA codes for proteins:DNA is the template for RNARNA is the template for proteins" What are ribosomes? the ribosomes is an ancient, complex, molecular machine made from protein and RNAProteins are synthesised o riboso,es using RNA as the template What is protein function determined by? By the 3D shape - which is determined by the amino acid sequence What type of chains are proteins? LINEAR How many standard amino acids are there? 20 (plus post-translationally modified ones) What 2 types of code do all amino acids have? 3 letter code1 letter code List the names and 3 letter codes of ALL 20 amino acids: Alanine - AlaArginine - ArgAsparagine - AsnAspartate - AspCysteine - CysGlutamine - GlnGlutamate - GluGlycine - GlyHistidine - HisIsoleucine - IleLeucine - LeuLysine - LysMethionine - MetPhenylalanine - PheProline - ProSerine - SerThreonine - ThrTryptophan - TrpTyrosine - TyrValine - Val Give the names of ALL 20 amino acids: (and write them down so you know the spelling) AlanineArginineAsparagineAspartateCysteineGlutamineGlutamateGlycineHistidineIsoleucineLeucineLysineMethionine PhenylalanineProlineSerineThreonineTryptophanTyrosine Valine Give the 3 letter codes of ALL 20 AMINO ACIDS: AlaArgAsnAspCysGlnGluGlyHisIleLeuLysMetPheProSerThrTrpTyrVal Give the names and 3 letter codes of the 4 amino acids starting with an A: Alanine - AlaArginine - ArgAspragine - AsnAspartate - Asp Give the names and 3 letter code of the amino acid starting with an C: Cysteine - Cys Give the names and 3 letter codes of the 3 amino acids starting with an G: Glutamine - GlnGlutamate - GluGlycine - Gly Give the names and 3 letter code of the amino acid starting with an H: Histidine - His Give the name and 3 letter code of the amino acids starting with an I: Isoleucine - Ile Give the names and 3 letter codes of the 2 amino acids starting with an L: Leucine - LeuLysine - Lys Give the name and 3 letter code of the amino acids starting with an M: Methionine - Met Give the names and 3 letter codes of the 2 amino acids starting with an P: Phenylalanine - PheProline - Pro Give the name and 3 letter code of the amino acid starting with an S: Serine - Ser Give the names and 3 letter codes of the 3 amino acids starting with an T: Threonine - ThrTryptophan - TrpTyrosine - Tyr Give the name and 3 letter code of the amino acid starting with an V: Valine - Val Describe the chirality of amino acids: "Optical isomersalpha carbons are asymetric so there are 2 stereoisomers: L and D" With which type amino acids can ribosomes form oeptide bonds between? Ribosomes ONLY form peptide bonds between L-amino acids What is the primary sequence of proteins? The sequnce of amuno acids in the polypeptide chain " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the parts of this tripeptide: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " Describe the experiment with urea that led us to believe that a protein's shape is determied by its amino acid sequence:Explain the results of this investigaiton: "This means that proteins don't need outside molecules to reform/refold - all information needed to refold is contained within the protein" What is a protein's shape determined by? Its amino acid sequence Its 3D shape is determined by the physiochemical interaction of its amino acids List all the different physiochemical interactions that amino acids can have within a protein: (6) Ionic interactions (salt bridges)Hydrogen bondsVan der Waals (steric) interactionsHydrophobic interactionsCovalent bondsDisulfide bonds What is the side chain/R group of Alanine (Ala)? "" What is the side chain/R-group of Cysteine (Cys)? "" What is the side chain/R-group of Aspartate (Asp)? "" What is the side chain/R-group of Glutamate (Glu)? "" What is the side chain/R-group of Phenylalanine (Phe)? "" What is the structure/R-group of Glycine (Gly)? "" What is the side chain/R-group of Histidine (His)? "" What is the side chain/R-group of Isoleucine (Ile)? "" What is the side chain/R-group of Lysine (Lys)? "" Whats the side chain/R-group of Leucine (Leu)? "" What is the side chain/R-group of Methionine (Met)? "" What is the side chain/R-group of Asparagine (Asn)? "" What is the side chain/R-group of Proline (Pro)? "" What is the side chain/R-group of Glutamine (Gln)? "" What is the side chain/R-group of Arginine (Arg)? "" What is the side chain/R-group of Serine (Ser)? "" What is the side chain/R-group of Threonine (Thr)? "" What is the side chain/R-group of Valine (Val)? "" What is the side chain/R-group of Tryptophan (Trp)? "" What is the side chain/R-group of Tyrosine (Tyr)? "" What are teh 5 amino acids with charged side chains? "" Explain how the charge on a protein can vary:Use lysine as an example: "The charge on a protein varies according to the amino acid sequence and the pH.E.g. lysine's side chain can very between 0 and +1" What happens to the charged amino acids when they get ionised? If H binds to any O- , it becomes an acid (e.g. aspartate ---> aspartic acid) What kind of physiochemical electrostatic interactions do charged amino acid sidechains form? "Ionic bonding - the ""salt bridge""" What are the 4 amino acids with polar sidechains? "" What type of physiochemical electrostatic interactions do polar sidechains form? "Hydrogen bonds " What are the 6 amino acids with aliphatic sidechains? "" What physiochemical electrostatic interactions do aliphatic sidechains form? Van der Waals interactions Describe how Van de Waals interactions come to be: "Atoms behave (almost) as if they are soli spheresAtoms sharing electrons (covalent bonds) are brought unusually close togetherWhen brought together atoms not sharing electrons experience Van der Waals interactions:          - it is not energetically favourable to share electronsincreased energy -= increased repulsion decreased distance between nuclei = increased repulsion - energetically favourable" What are we trying to maximise when we compress a protein? We are trying to maximise the Van der Waals interactions therefore have the maximum hydrophobic effectthis is why hydrophobic proteins fold to the middle/core of a protein (in an aqueous protein) Describe the hydrophobic interactions within a protein: "non-polar side chains tend to be buried in the core of the proteinpolar side chains on teh outside of the molecule can form hydrogen bonds with water " What are the 3 amino acids with aromatic sidechains?What is another thing that is special about these 3 side chains "These 3 sidechains are fluorescent, especially Trp" Would tryptophan's side chain be buried in the core of a protein? Why? Yes and no and maybeIt is difficult to find a place for it (due to the ring) so it is usually faced down with NH on the outside to form interactions (e.g. H-bonds) Describe whats secial about Proline and explain why it can be problematic: "Proline disrubts the backbond hydrogen bonding network in beta sheets and alpha helices and are often found at the extremities of these 2º structuresIt is the only side chain that attaches to an amide nitrogen, thus the backbone is not free to rotate around N thus restricted rotations so can only form specific shapes~10% of prolines are in the cis conformation and introduce kinks in the protein backbone" Describe the covalent bonds that form between cysteine sidechains: "When cystein amino acids are oxidised, they can form disulfide bonds" " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " What is the primary structure of a protein? The sequence of amino acids in a polypeptide chain What is the secondary structure of a protein? the regular re[eated structures found in many proteins:Alpha-helices and beta sheets are by far the most common What is the tertiary structure of a protein? The conformation (3D shape) of a single polypeptide chain What is the quanternary structure of a protein? The conformation (3D shape) of a protein that consists of >1 polypeptide chain Describe th features/properties of alpha helices: "Around 25% of all soluble proteins are mainly alpha helicesNormally right-handed twist/spirallingTightly packed - no free space insideSide chains pointing out (extend out and up)Alpha helices can assemble to make coiled coilsFavoured residues are metionine, alanine, glutamate and lysine (MALEK)Unfavoured residues are proline glycine and aspartate (PGD)Evey carbonyl oxygen forms a H-bod with the amide hydrogen i+4alpha helices are favoured due to thisthe more bonds we can form, the more stable the structure will be" Draw an alpha helix: "" Describe the hydrogen bonding between backbone atoms in an alpha helix: "Every carbonyl oxygen forms a H-bond witht he amide hydrogen i+4 The oxygens and nitrogens point in opposite directionsThe R-groups extend out and up" "What do the 2 numbers on the drawing mean?" 5.4 B = the rise - the rise every time the helix turns around3.6 residues = the amount of residues we need to go around An alpha helix has the sequence 12345671234567123.. where only 1 and 4 are hydrophobic What is the likely structural consequence/outcome? "The helix will form a dimer due to the hydrophobic effect - hydrophobic molecules like to come togetherHydrophobic sidechains 1 and 4 form a hydrophobic patch/stripe.In aqueous solutions, helices are forced together by the hydrophobic effect" What are the other 2 helices that can be found in proteins other then alpha (VERY RARE): "The 310 helic is occasionally found, i+3         - too tight of a helixAs is the π (pi) helix, i+5        - too loose of a helix" When non-alpha helices are found ehat do they look like? How is this useful to us with proteins? "They are normally short sections and they normally interrupt the alpha helixthis is how we can start to for proteins of different shapes" Describe beta sheets: "Hydrogen bonding between adjecent backbonescan be parallel and anti-parallel (anti-parallel are slightly more favoourable than the parallel)" Draw/sketch beta sheets: "" "Describe the directionality of the side chains in these anti-parallel beta sheets:" "Sidechains are extended out and alternating up and down directionsevery other R-group is upyou can have proteins that 1 side is hydrophobic and the other is hydrophilic due to teh directionality of the sidechains" Which primary sequences can form beta sheets? ANY primary sequence can form beta sheetsEXCEPT proline What is a protein domain? A distinct structural or functional unit within a protein Describe how retinol is transported around the blood: "Inside a retinol-binding protein, a beta-barrel composed of anti-parallel beta strands joined by loops" What are the other 2 common secondary structures? Describe: Loops Turns     - the reverse turn is often found linking beta strands (also known as a beta-hairpin)Loops and turns often form the most variabke and biologically active parts of proteins What is another type of helix other than alpha, 310 and π? Describe: "Collagen triple helix It is composed of 3 polypeptide chains with very conserved sequencesEvery 3rd residue is Gly and there are many Pro and Hyp (hydroxyproline - formed by post-translational modification fo Pro) residuesIt is conformationally restricted due to the high proportion of proline residues" Why in a triple collagen helix does every 3rd residue have to by glycine? "Glycine is the only residue small enough to fit in the middle/core." What can beta barrels be used for? Example: To transport hydrophobic molecules around the bodyE.g. retinol (vitamin A) which is insoluble in water (and therefore also blood) "How is the ""Greek key"" supersecondary motif formed?" "By folding a β-hairpin over 2 β-strands - very common in proteins." What are the 3 types of supersecondary motifs? "" Why are supersecondary structures important? Superseconday structures are the building blocks of most proteins How are supersecondary structures stabilised? The helices' and sheet's primary sequences must be complementary to each other "Describe the properties/features of this supersecondary structure 9and supersecondary structures in general):" "The same domains are found in seemingly unrelated proteins4 helix bundles like the 1 on the right are found in many different proteinsHere 2 alpha-alpha motifs combine into a 4-helix bundle domain in cytochrome B562 Note the heme prosthetic group bound betwee the helices" What is triose-phosphate isomerase structure formed from (structurally)? "from 8 parallel β-strands and 8 parallel α helices to form an αβ barrel.Around 10% of all known enzyme structures take this form" Descirbe the immunoglobin (Ig) fold:(one of the most common domains found in nature) "In the immunoglobin fold 7 anti-parallel β strands fold to form a β-sandwichIt's similar to an extended Greek key" Why do proteins fold? To satisfy the sum of their molecular interactions What happens if a protein adopts an incorrect structure? Misfolding proteins can lead to a lot of diseases (especially neurodegenerative diseases). What does Anfinsen's dogma state? That protein structure is determined by its primary structure What deos molecular recognition depend on? Ligand binding What is molecular recognition? How a molecule recognises/knows what it needs to bind to What substances can be ligands? Atoms, ions, molecules or macromolecules Give examples of ligand binding: (6) Substrate bind to enzymesSingle-stranded DNA binds complementary DNATranscription factors bind to DNADrugs bind to enzymes (or other types of protein)Hormones bind to specific receptorsAntibodies bind to antigens Describe allosteric interactions?: "Allosteric proteins bind to multiple ligands" Describe non-allosteric interaction: "Non-allosteric proteins only bind to 1 ligand" What is affinity? A measure of how tightly a protein binds to a ligand Describe the functions of Hb in comparison to Mb: Hb transports O2 from lungs ---> releases in tissues. It also transports CO2 and H+ from tissues ---> releases in lungs.Mb stores (binds and releases) O2 in musclesBoth Mb and Hb can bind, transport and detoxify NO, which is a vasolidator and inhibitor of platelet aggregationBoth Mb and Hb are globular proteins with tightly-packed cores Describe the structure of Hb in comparison to Mb: Both are globular proteins with tightly-packet cores.Haemoglobin (Hb):4 polypeptide chains.       - In ADULTS: 2 alpha-chains and 2 beta-chains (HbA1).       - In FOETUSES: 2 alpha-chains and 2 gamma-chains (HbF)alpha-chains: 141 amino acidsbeta-chains: 146 amino acidsEach chain binds a haeme prosthetic groupMyoglobin (Mb):1 polypeptide chain and 1 haeme group.154 amino acids~25% identical to Hb chainsThe conformation (the 2º and 3º structure) is very similar to Hb chain What transition metals are epecially essential to biology? IronCobaltCopperMolybdenum Why are transition metals essential to biology? "As metal ions bind a discrete n.o ligands to form ""coordinate"" (""dative covalent"") bonds which share a pair of electrons donated by the same atoms" What are the common donor atoms in metal ion-ligand complexes? N, O , S What is a monodentate ligand? "they donate a single pair of electrons to the metal ion" What is a polydentate ligand? a ligand that donates ≥2 pairs of electrons to metal ions Describe the Haeme prosthetic group: "It is a porphryin ring that sits in a hydrophobic cavity on the surface of the subunitO2 binds to the Fe2+ ion in the centre of the ringThis ion is always in the Fe2+ ferrous (2+) state.It is polydentate, binding up to 6 ligands: 4 haeme N, 1 His side-chain (the ""proximal histidine"") and O2." When does the Ferrous (Fe2+) irin oxidise to ferric (Fe3+) iron in Hb? Only if haeme is stripped from the protein What is a special of property of haeme (HINT: in the absence vs presence of O2)? "The Fe2+ has 5 ligands and a larger atomic radius than in the O2-bound stateThe larger radius means that the Fe2+ doesn't fit in the plane of the porphyrin ring in deoxy-Hb       - the Fe2+ is pushed down out of the plane of the porphyrin ringThe O2 forms a H-bond ith another His side chain - the ""distal histidine"" that stabilises the O2-Fe2+ interaction" What stabilises the O2-Fe2+ interaction in the Haeme group in Hb? "The O2 that forms a H-bond with another His side chain - the ""distal histidine""" How well conserved protein is Mb? Mb is a very well conserved proteinMb is well conserved between species In general what does it mean if 2 proteins are >30% identical? They will have a similar backbone shape " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " Describe the law of mass action:The equilibriumWhat is vf = [P].[L].ka?What is vr= [P:L].kd? "The velocity of the forward reaction is dependent on ka and the concentration of the protein and ligand The velocity of the reverse reaction is dependent on kd and the concentration of the protein:ligand complex" Define the dissociation constant Kd:Units: kd/ka therefore = [P][L]/[P:L]It describes the concentrations of P, L and P:K at equilibriumUnits: moles.L-1 What is the fraction Y? The fractional saturation - how many ligand binding sites are occupiedY vaires between 0.0 and 1.0 What does it mean if Y=1.0? All ligands are bounded to proteins What is the most important equation in biology to find Y? Y = [L]/(Kd + [L])Described how well a lignad binds to a protein What is another equation for Y (not the most important in biology)? Y = [P:L]/([P:L] + [P]) What is the factional saturation when [ligand] = Kd? 0.5 What type of curve is the curve described by this equation?Y = [L]/(Kd + [L]) "A Hyperbolic curve" What does the Y mean when [L] is low? "At low [L], very few binding sites are occupied" What does the Y mean when [L] = Kd? "When [L] = Kd, half the binding sites are occupiedThe Kd is the [L] rerquired to occupy half the binding sites" What does the Y mean when [L] is much greater than Kd? "When [L]>>Kd most of the bidning sites are occupied" Describe what the Y vs [L] curve would look like for when 2 different proteins can bind to the same ligand with different affinities: "Both curves will eventually reach Y=1, the bthe Kd=8 (red) protein is at a lower fractional saturation than the Kd=4 (blue) protein at any given [L]" Describe the effect on Y whena ligand (eg. drug) can bind to 2 different proteins with edifferent affinities: "At any given [drug], the Y of the desired target will be > than that of the non-specific target" Why do some drugs cause side effects? "They may bind to the wrong proteinperhaps drug might bind to non-specific target as well, causing side-effectsas at any given [drug], Y of desired target > non-specific target " What can O2 binding to Mb and Hb be measured with? "Using a spectrophotometer" What is P50 in a Y vs pO2 graph? Dissociation constantP50 = [O2] required to occupy 1/2 the binding sites Give the equation for Y in Mb binding sites: Y = pO2 / (P50 + pO2) What do we measure [O2]/pO2 in? torr (mm Hg) What type of curve is the oxygen binding to Hb? Sigmoidal What type of curve is the oxygen binding to Mb? Hyperbolic What is P50 in an Oxygen bidning to Hb sigmoidal curve? 26 torr What is P50 in an Oxygen bidning to Mb hyperbolic curve? 2 torr What is the pO2 in:Lungs:Resting tissues:Exercising tissues: ~100 torr~40 torr~20 torr Why is Hb a better delivery protein than Mb? As the sigmoidal curve allows Hb to deliver ~x10 as much O2 to exercising tissues as MbMb is useless as a delivery protein as it wouldn't release any O2, whilst Hb is good at realeasing O2 where needed (due to sigmoidal curve and Kd)P50 of Hb is x13 larger than Mb What are the 2 structural forms of Hb? Describe: "Deoxyhaemoglobin      - Tense form (T-form)      - Low affinity for O2 Oxyhaemoglobin      - Relaxed form (R-form)      - High affinity for O2 " What does it mean when Hb has positive cooperativity? Why does Hb have positive cooperativity? Binding of O2 to 1 subunit increases the binding affinity of the other sitesthe sigmoidal binding curve indicates thisReleasing O2 from 1 subunit makes it easier to release the other 3 O2 from the other 3 subunits Describe how cooperativity can be diagnosed: "Using a Hill Plot" Describe how the R-state and T-sate bindign curves look like and how that relates to how the observed Hb binding curve looks like: "" Describe the concerted model for cooperativity: "All subunits exist in either the T or the R stateThe P50 for the R state < P50 for T stateAs O2 binds the eq. shifts from favouring the T-state to favouring the R-stateAs pO2 increases, R state is favoured As pO2 decreases, T state is favoured" What does allosteric mean when referring to Hb? Binding to Hb at a site other than the O2 binding site Describe the function of the 2,3-bisphosphoglycerate (2,3-BPG) allosteric effector: "It is present in low concentrations in all cells but approx. eqimolar eith Hb in RBCsIt is over-prodiced in response to high-altitude, airway obstruction or congestive heart failureBinds more tightly to deoxy-Hb (T-state) than oxy-Hb (R-state)Without 2,3-BPG Hb wouldn't release O2, thus we would suffocateBPG stabilises the T-state and so increases the P50 BPG + oxy-Hb ↔ deoxy-Hb-BPG + 4O2 " Descfribe how 2,3-BPG explains how O2 is tranferred to foetal blood: "BPG has a lower affinity for HbF than Hb so HbF has a smaller P50 for O2 than Hb HbF binds O2 more tightly than Hb" What is the bohr effect? "When protons (H+) bind preferentially to deoxy-Hbdeoxy-Hb-H+ + 4O2 ↔ Oxy-Hb + nH+ n is a number between 1.7 - 2.7" Describe the Bohr effect: "deoxy-Hb-H+ + 4O2 ↔ Oxy-Hb + nH+Le Chantelier's Law: if the [H+] increases, the eq. shifts to the left. As the pH drops, O2 is releasedHb acts as a buffer" Describe how in the Bohr effect the H+ binds: "Protons (H+) bind preferentially to doexy-HbOnly in the T-state (deoxy-Hb) are the 3 residues oriented to enable the formation of 2 salt bridges that help to stabilize the T-state" Describe the CO2 binding in the Bohr effect:What does this mean for the alloestic effect? "CO2 can bind directly to the N-terminal groups of Hb by forming carbamateThe carbamate partipates in salt bridges that help to further stabilise the T-stateCO2 reduces the affinity for O2 beyond that caused by a drop in pH aloneThis illustrates a general rule: allosteric affects are cumulative" Describe the mutations that can occur in Hb (include at least 1 example): "In general, mutations that occur on the surface of Hb have no phenotype (they are ""silent"" mutations).Mutations in the interior are rarely silent and often result in hemolytic anaemia>1000 variants are knownMost are single residue substitutionsExamples:E6V mutationHammersmith beta F42S (increased P50)Bristol beta V67D (increased P50)Boston alpha H58Y (increased methemoglobin formation)Kansas beta N102T (disrupts H-bond that stabilises R-state)" Describe the E6V mutation in Hb: "The E6V mutation in Hb produces HbSThe most famous mutation in Hb is glutamic acid ---> Valine at position 6 in the beta chainThe E6V mutation a hydrophobic patch on the surface of Hb.This can interact with an existing hydrophobic patch on the surface of T-state Hb and results in sickle cell anaemia HbS forms fibres Sickle cell reduces the 1/2 life of RBCs These cells block  capillaries, causing inflammationa dn painPeople who are homozygous for the mutaitonn are often seriously debiliated and don't survive into adulthood" 20 amino acids: Glycine3 letter code1 letter codeStructurePropertiesInteresting facts (2)Mnemonics "GlyG- Very small (smallest)- Hydrophobic- Not liked by alpha helix1) In collagen triple helix2) Makes backbone flexibleGlyyyycine is tiiiiiny" 20 amino acids: Alanine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "AlaA- Small- Hydrophobic - Nicely fits into alpha helixOften sought in site directed mutagenesisSimilar to serine but doesn't have OH" 20 amino acids: Valine3 letter code1 letter codeStructurePropertiesMnemonics "ValV- A bit bulky due to the 2 methyls- Very hydrophobic - binding pocket for elastaseThe 2 methyls of side chain look like ""V"" for Valine" 20 amino acids: Proline3 letter code1 letter codeStructurePropertiesInteresting facts (2)Mnemonics "ProPThe strangest amino acid- Makes a loop- Binds to backbone- hydrophobic1) Can form cis peptide bonds (cis-prolyl isomerase)2) Not liked by alpha helixProline is PRO because only she/he can do cis bonds " 20 amino acids: Leucine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "LeuL- Very hydrophobic- Very bulky (but not aromatic!)Isomer of isoleucineLeucine is Lucy with long hair = long side chains" 20 amino acids: Isoleucine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "IleI- Very hydrophobic- Very bulky (but not aromatic!)Isomer of LeucineStructure is only slightly different from leucine" 20 amino acids: Methionine3 letter code1 letter codeStructurePropertiesInteresting facts (1) "MetM- Very hydrophobic Has sulphur but can't do disulphide bonds...(Sulphur locked)" 20 amino acids: Phenylalanine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "PheF- Hydrophobic and aromatic- BulkyForms π-π stacking interactionsPhenylalanine for phenyl ring + Phe = F" 20 amino acids: Tyrosine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "TyrY- Hydrophobic with a bit of polarity on OH- Aromatic1) Receptor Tyrosine KinasesTyrosine = Y, similar to phenylalanine" 20 amino acids: Tryptophan3 letter code1 letter codeStructurePropertiesMnemonics "TrpW- Hyrdophobic with a bit of polarity on NH- AromaticNOT charged" 20 amino acids: Serine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "SerS- Polar- OH group- A bit smallCatalytic triat in serine proteasesSimilar to alanine but with OH" 20 amino acids: Cysteine3 letter code1 letter codeStructurePropertiesInteresting facts (3)Mnemonics "CysC- Polar- Sulphur- A  bit small1) forms disulphide bonds2) Important for 3º/4º structure3) Catalytic residue in proteasesCySSS for Ssssulfur" 20 amino acids: Threonine3 letter code1 letter codeStructurePropertiesMnemonics "ThrT- Polar- OH group- A bit biggerA bit similar to Valine" 20 amino acids: Asparagine3 letter code1 letter codeStructurePropertiesInteresting facts (1) "AsnN- -CONH2 - LongerHas an amide in its sidechain" 20 amino acids: Glutamine3 letter code1 letter codeStructurePropertiesInteresting facts (1) "GlnQ- -CONH2 - LongerHas amide in its sidechain" 20 amino acids: Lysine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "LysK- +ive- LooongIMPORTANT - lots of ionic interactionsStrange: Lys = K" 20 amino acids: Arginine3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "ArgR- +ive- Long- ""like aromatic""IMPORTANT - think ""ion channels""R for Arginine" 20 amino acids: Histidine3 letter code1 letter codeStructurePropertiesInteresting facts (1) "HisH- +ive or neutral - depending on local environmentTHE MOST IMPORTANT - in catalytic triad of proteases" 20 amino acids: Aspartic acid3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "AspD- Always -ively charged (be careful)IMPORTANT - catalytic triad""Like"" asparagine" 20 amino acids: Glutamic acid3 letter code1 letter codeStructurePropertiesInteresting facts (1)Mnemonics "GluE- Always -ively chargedIMPORTANT""Like"" glutamine" List all the hydrophobic amino acids in order of increasing bulkness: (10)Name3 letter code1 letter code Glycine, Gly, GAlanine, Ala, AValine, Val, VProline, Pro, PLeucine, Leu, LIsoleucine, Ile, IMethionine, Met, MPhenylalanine, Phe, FTyrosine, Tyr, YTryptophan, Trp, W List all the hydrophilic amino acids in order of increasing chai length: (5)Name3 letter code1 letter code Serine, Ser, SCysteine, Cys, CThreonine, Thr, TAsparagine, Asn, NGlutamine, Gln, Q List all the +ively charged amino acids: (3)Name3 letter code1 letter code Lysine, Lys, KArginine, Arg, RHistidine, His, H List all the -ively charged amino acids: (2)Name3 letter code1 letter code Aspartic aci/Aspartate, Asp, DGlutamic acid/Glutamate, Glu, E Why do proteins need to be purified? To remove anything thst interferes with your experiments       - Interfering compounds can include inhibitors, activators, aggregated or denatured proteins       - Often we need to remove proteins, such as isoforms, with related activitiesImpure proteins are very resistant to forming the crystals that are required for X-ray crystallography Describe the sources of proteins used for purification: Before molecular biology was possible, proteins were purified from tissues or cells that naturally contained a high proportion of protien of interestMolecular biology has increased the potential sources of proteins:ProkaryotesUnicellular eukaryotesMammalian cells Explain the ADVANTAGES of using prokaryotes in protein production:Example: Escherichia coli (E.coli)ADVANTAGES:V easy to genetically manipulateV east to grow in large quantities in liquid culturepotentially V high yields of protein Explain the DISADVANTAGES of using prokaryotes in protein production:Example: Escherichia coli (E.coli)DISADVANTAGES post-translational modificatiols will probably be different to those used in eukaryotic cells            - eg. mammalian-like protein glycosylation not possiblePoor at folding proteins           - e.g. multi-subunit proteins or ones with a high-disulfide bond content Explain the ADVANTAGES of using unicellular eukaryotes in protein production:Example: YeastADVANTAGES:Easy to genetically manipulateEasy to grow in large quantitiesPotentially high yieldsPost-translational modifications more similar to mammalian ones - including glycosylation Explain the DISADVANTAGES of using unicellular eukaryotes in protein production:Example: YeastDISADVANTAGES:Only moderate ability to fold complicated proteins Explain the ADVANTAGES of using mammalian cells in protein production:Example: HEK cells (Human Embryonic Kidney)ORHeLa cells (Henrietta Lacks)ADVANTAGES:Full range of mammalian post-translational modificationsAbility to form and assemble complicated proteins Explain the DISADVANTAGES of using mammalian cells in protein production:Example: HEK cells (Human Embryonic Kidney)ORHeLa cells (Henrietta Lacks)DISADVANTAGES:Less easy to genetically manipulateHard to grow in large quantitiesPoor yields of proteinV expensive growth media How do we know if the protein you want is present in a sample? Test for activity by doing an assayAn assay is a test for the presence of something What is the most common technique for purifying large quantities of protein? Describe: "Column chromatographyThe solution containing the protein mixture, the ""liquid phase"", is added to a porous solid matrix, the ""stationary phase""The matrix - based on polymers such as agarose or cellulose - interacts with proteins according to their physiochemical properties" What are the 4 types of column chromatography? Gel filtration chromatography - separates on the basis of protein size Ion exchange chromatography - separates on the basis of protein charge  Hydrophobic interaction chromatography - separates on the basis of protein hydrophobicityAffinity chromatography - separates on the basis of specific protein interactions, such as enzyme binding to a substrate, or an antibody to an antigen Describe gel filtration chromatography: "Also known as Size Exclusion or Molecular Exclusion ChromatographySeparates proteins according to size       - Big proteins come out first and small proteins last - as small molecules enter to aqueos spaces within beads wheareas large molecules can't" Describe ion exchange chromatography: "Separates proteins according to their charge" Explain what titration curves describe (according to proteins): "They describe how a protein's charge varies with -pH Proteins with many acidic residues will be more -ively chargedProteins with many basic residues will be more +ively charged" Describe the shape of a titration curve of a protein (overall charge vs pH): "" Define the isoelectronic point (pI): "The pH at which a protein has no overall charge (zwitterionic)When pH>pI, the protein is -ively chargedWhen pH<pI, the protein is +ively chargedThe pI of manny proteins is ~5 or ~9" How are titration curves useful to us when we are identifying proteins and purifying proteins in column chromatography? "By knowing the isoelectronic point we know the pH at which the protein is zwitterionic.Therefore by altering the pH of the buffer, we can alter which proteins bind to the column" Describe are the 2 types of Ion Exchange Chromatography (IEX) and media: "We cna choose IEX media with a permanent +ive or -ive chargeBy changing the pH of the buffer proteins can be made to bind to an IEX column - or not bind2 common IEX media:        1) DEAE cellulose (+ive)        2) CM cellulose (-ive)" What are the 2 way to elute (unbind) a protein from an IEX column? "Change the pH of the buffer flowing through the column to change the charge on the protein (seldom used, it's more difficult to control)Increase the buffer's [salt] to elute the protein via ""charge shielding""        - Elution can be a step-wise e.g. sequentially apply buggers containing 0.1, 0.25, 0.5, 1.0M NaCl        - Or can be done via a gradient of steadily increasing salt e.g. 0 ---> 1.0M NaClGradient elution has a higher resultion than step-elution." Describe the A280 method of protein detection: "MOST  IMPORTANT!An A280 signal - or any other non-specific method of detecting proteins - tells you how much protein is presentBut it CAN'T tell you how many types of protein are present" How do you tell if a chromatography fraction contains only 1 protein? "Use sodium dodecyl sulfate polyacrylamide gel electrophoresis ""SDS-PAGE""SDS-PAGE separates proteins on the basis of their subunit size  It's the standard check of purity for chromatography fractions" What is SDS-PAGE? Sodium Dodecyl Sulfate Polyacrylamide Gel ElectrophoresisIt separates proteins on the basis of their subunit size  It's the standard check of purity for chromatography fractions Describe how to carry out SDS-PAGE electrophoresis: "An acrylamide gel has pores about the same size as most proteins and acts as a molecular sieve Mixtures of SDS- and heat-treated proteins are applied to the top of the gelSDS- gives proteins a -ive charge, heat makes them the same shapeA voltage is applied to the gel and the proteins migrate towards the +ive electrode (anode) accroding to their sizeProteins run from the top ---> bottomAfter electrophooresis the gel is stained (often with coomassie blue ) to visualise the proteins" When is SDS-PAGE most effective? Why? Most effective when combined with activity assaysAs SDS-PAGE only tells you the proteins that have the same molecular weightThats why SDS-PAGE combined with an activity assay is a good way to assess purity What is the problem with total protein detection methods (e.g. A280)? They will only tell you the concentrstion of proteins, not how pure they are What are enzymes? Biological catalysts, usually proteins, that speed up chemical reactions in living organisms without being consumed in the reactionThet are typically proteins ranging in sizeThey often contain bound co-factors (sometimes called coenzymes) which contribute to the catalytic mechanisms (e.g. biotin, metal ions, thiamine pyrophosphate, NAD+/NADH, niacin, haem,etc.) Describe the similarities and differences between chemical catalysts and enzymes as bioogical catalysts: "LIKE catalysts used in chemical reactions, enzymes:catalyse (by more than 106-fold) the rate at which chemical reactions attain equilibrium, but without affecting the equilibrium position of the reaction  are unchanged in the overall reaction that they catalyseUNLIKE chemical catalysts, enzymes have evolved to have:high substrate specificityVery high catalytic powerCatalytic power under ""gentle"" reaction conditions (e.g. pH6-8, 37ºC) " Define kcat: it is equivalent to the n.o substrate molecules in a single molecule of enzyme can bind and convert to product every second (when substrate is unlimited) What are the 3 things we can measure to determine enzyme activity? the rate of production of productthe rate of loss of the substratethe rate of production or loss of a co-factor involved (i.e. NAD+/NADH)All of this can be done in an enzyme assay What is the formula for the enzyme activity? "" What results do we usually expect as well as expectations for enzyme activity during an enzyme assay? reaction rate to be proportional to the enzyme concentration               - double enzyme concentration = rate doublesat higher enzyme concentrations the substrate may be used up during the measurement (the absorbance tails off).                - It is important to measure the initial rate by drawing a tangent to the curve at a time shortly after adding the enzyme. the key experiment for characterizing the kinetic parameters of an enzyme, its interaction with substrate, and the effects of inhibitors, is the measurement of reaction rate as a function of substrate concentration (keeping the enzyme concentration constant) Define an enzyme activity unit: the amount of enzyme which transforms 1 µmol of substrate per minute at 25ºC Define the specific activity of an enzyme: the n.o enzyme units per milligram (mg) of proteina measure of purity What are the 2 things we want to maximise in each enzyme purification? the recovery of the enzymethe purity of the enzyme        - the specific activity should increase! Formula for % recovery: "" Formula for degree of purification: (specific activity purification) / (specific activity crude) What are the 3 ways that substrances can inhibit enzymes/uses of enzyme inhibition? Biologically - one of themechanisms for controlling enzyme-catalysed reactions in vivo Therapeutically - many drugs (and toxins) are enzyme inhibitorsMechanistically - our understanding of enzyme mechanisms often involves studying the effect of inhibitors What are the 2 types of inhibitors? Irreversible inhibitors - the enzyme is irreversibly inactivated by covalent or tight binding of inhibitor, usually to enzyme active siteReversible inhibitors - competitive or non-competitive  Describe the differences between competitive and non-competitive inhibitors: "COMPETITIVEcompetes directly with the substrate for binding to the active siteit is usually a substrate analoguethe inhibitor's effect can be overcoe at high enough [S]e.g. HIV protease and crixivan (anti-A.I.D.S. drug)e.g. Prostaglafin synthase with IBUPROFEN blocking active site accessNON-COMPETITIVE :doesn't compete directly with the substrate for binding to active site (substrate and inhibitor can both be bound at once)." Describe competitive inhibition: "competes directly with the substrate for binding to the active siteit is usually a substrate analoguethe inhibitor's effect can be overcoe at high enough [S]" Describe non-competitive inhibition: "doesn't compete directly with the substrate for binding to active site (substrate and inhibitor can both be bound at once).Km is therefore little affected" How can competitive and non-competitive inhibitors be distinguished kinetically? "Compare double reciprocal (Lineweaver-Burk) plot for th enzyme reaction in the presence of an inhibitor, and its absence, respectively" How do you determine Km and Vmax using a Lineweaver-Burk Plot: "" Describe the  difference between irreversible and reversible enzyme inhibitors (using examples): "IRREVERSIBLE:the enzyme is irreversibly inactivated by covalent or tight binding of inhibitor, usually to enzyme active sitee.g. ACh with DIPF - toxin/poisone.g. prostagladin synthase (cyclooxygenase; COX) with aspirin - therapeutice.g. trypsin with pancreatic trypsin inhibitor - regulation (of protein digestion in the gut)REVERSIBLE:competitive or non-competitivecompetitive - competes directly with the substrate for binding to the active site        - e.g. HIV protease with Crixivan (anti-A.I.DS. drug)            - e.g. prostagladin synthase with IBUPROFEN blcoking active site accessnon-competitive - doesn't compete directly with the substrat for binding to active site (substrate and inhibitor can both be bound at once). Km is therefore little affected." Describe the effect of competitive inhibitors on the values of Km and Vmax: "" Describe the effect of non-competitive inhibitors on the values of Km and Vmax: "" How do we measure the effects of competitive and non-competitive inhibitors on the values of Km adn Vmax using enzyme assays? "Can be distinguished kinetically!We compare double reciprocal (Lineweaver-Burk) plot for the enzyme reaction in the presence of an inhibitor, and its acsence, respectively" Why can't you use A280 chromatogram to identify types of enzymes? As ALL PROTEINS  absorb light at 280nm " Lable the bacteria cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable the bacteria cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.style.display === '') amask.style.display = 'none'; else amask.style.display = 'block' } // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: // Prevent original image from loading before mask aFade = 50, qFade = 0; var mask = document.querySelector('#io-overlay>img'); function loaded() { var original = document.querySelector('#io-original'); original.style.visibility = ""visible""; } if (mask === null || mask.complete) { loaded(); } else { mask.addEventListener('load', loaded); } " " Lable this eukaryotic cell: Toggle Masks // Toggle answer mask on clicking the image var toggle = function() { var amask = document.getElementById('io-overlay'); if (amask.style.display === 'block' || amask.sty

Year 1 Biochemistry Cellular Composition (BCC) Notes PDF

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