Fundamentals of Chemistry
44 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the relationship between the acid dissociation constant (ka) and the pKa?

High ka corresponds to low pKa and vice versa.

Define a strong acid and a weak acid in terms of dissociation in aqueous solution.

A strong acid completely dissociates, while a weak acid only partially dissociates.

How can the ionic product of water (Kw) be expressed in relation to the concentrations of hydrogen and hydroxide ions?

Kw = [H+][OH-] = 1 x 10^-14 mol² dm^-6.

Explain the role of buffers in biological systems.

<p>Buffers help maintain a stable pH within a tolerable range for biological molecules.</p> Signup and view all the answers

Describe what happens to the concentration of H+ and A- at equilibrium for a weak acid.

<p>The concentrations of the undissociated acid and its conjugate base will be equal.</p> Signup and view all the answers

What role does flavin adenine dinucleotide (FAD) play in biological reactions?

<p>FAD acts as a hydrogen/electron acceptor in redox reactions.</p> Signup and view all the answers

How do you determine if a monosaccharide is an aldose or a ketose?

<p>An aldose has its carbonyl group at the end, while a ketose has it in the middle of the chain.</p> Signup and view all the answers

What is the significance of cyclisation in monosaccharides?

<p>Cyclisation results in the formation of new stereocenters and anomers, either α- or β- forms.</p> Signup and view all the answers

Describe the difference between amylose and amylopectin.

<p>Amylose is a linear chain of α-D-glucose, while amylopectin has branching due to α-1,6 glycosidic bonds.</p> Signup and view all the answers

What are the key characteristics of lipids?

<p>Lipids are long hydrocarbon chains that are amphiphilic, containing a hydrophilic head and a hydrophobic tail.</p> Signup and view all the answers

How is the saturation of fatty acids determined?

<p>A saturated fatty acid has no double bonds, while an unsaturated fatty acid contains one or more double bonds.</p> Signup and view all the answers

Explain the notation used to describe a fatty acid with 16 carbon atoms and no double bonds.

<p>This fatty acid is described as 16:0, indicating 16 carbons and 0 double bonds.</p> Signup and view all the answers

How do you designate the position of a double bond in fatty acids?

<p>The position is designated using ω- or n- notation, counting from the methyl group, e.g., ω-7.</p> Signup and view all the answers

What is the primary function of glucose-6-phosphatase in gluconeogenesis?

<p>It converts glucose-6-phosphate to glucose.</p> Signup and view all the answers

Which enzyme catalyzes the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate?

<p>Fructose-1,6-bisphosphatase.</p> Signup and view all the answers

Describe the process of converting pyruvate to oxaloacetate.

<p>Pyruvate is converted to oxaloacetate by pyruvate carboxylase in the mitochondrial matrix.</p> Signup and view all the answers

List three alternative precursors for gluconeogenesis besides pyruvate.

<p>Lactate, glucogenic amino acids, and glycerol.</p> Signup and view all the answers

What is normoglycemia, and why is it important?

<p>Normoglycemia is the condition of having normal blood glucose levels, which is essential for proper metabolic functioning.</p> Signup and view all the answers

What role does glucagon play in blood glucose regulation?

<p>Glucagon promotes gluconeogenesis and the conversion of glycogen to glucose when blood glucose levels are low.</p> Signup and view all the answers

How does insulin affect glycolysis when blood glucose levels are high?

<p>Insulin activates glycolysis, promoting the breakdown of glucose for energy.</p> Signup and view all the answers

Explain the differences between fast and slow regulation of glucose levels.

<p>Fast regulation involves inhibiting or activating enzymes in glycolysis and gluconeogenesis, while slow regulation involves hormonal changes like glucagon and insulin affecting gene expression.</p> Signup and view all the answers

What are the main differences between the primary and secondary structures of proteins?

<p>Primary structure is the sequence of amino acids linked by peptide bonds, while secondary structure is formed by hydrogen bonds and includes structures like α-helices and β-sheets.</p> Signup and view all the answers

Explain the role of chaperones in protein folding.

<p>Chaperones are proteins that assist in the correct folding of other proteins, ensuring they achieve their functional three-dimensional structure.</p> Signup and view all the answers

What is the significance of the isoelectric point in protein purification?

<p>The isoelectric point is the pH at which a protein has a net charge of zero, which enhances its separation in ion-exchange chromatography.</p> Signup and view all the answers

Describe how SDS-PAGE is used to analyze proteins.

<p>SDS-PAGE involves denaturing proteins to give them a negative charge, allowing them to migrate toward a positive anode where smaller proteins travel further.</p> Signup and view all the answers

What is the importance of the tertiary structure in protein functionality?

<p>Tertiary structure determines the overall 3D shape of the protein, which is crucial for its specific function and interactions with other molecules.</p> Signup and view all the answers

What role does Cytochrome C play in the electron transport chain?

<p>Cytochrome C shuttles electrons to complex IV and uses an iron atom to alternate between Fe(II) and Fe(III) states.</p> Signup and view all the answers

How does Complex IV contribute to the proton gradient in mitochondria?

<p>Complex IV reduces molecular oxygen to water by taking up four protons from the matrix and pumps four protons across the inner mitochondrial membrane.</p> Signup and view all the answers

Define proton-motive force and its components.

<p>Proton-motive force is the energy created by a chemical gradient and a charge gradient due to proton concentration differences on either side of a membrane.</p> Signup and view all the answers

Describe the function of ATP synthase in ATP production.

<p>ATP synthase allows protons to flow through its channel, facilitating the rotation of its c subunit, which catalyzes ATP synthesis during conformational changes.</p> Signup and view all the answers

What happens to the beta subunits of ATP synthase during ATP synthesis?

<p>The beta subunits undergo conformational changes that transition from loose to tight to open states, allowing ADP and inorganic phosphate to bind, ATP to form, and ATP to be released.</p> Signup and view all the answers

How does the malate/aspartate shuttle differ from the glycerol phosphate shuttle in terms of ATP yield?

<p>The malate/aspartate shuttle results in a net yield of 2.5 ATP, while the glycerol phosphate shuttle yields 1.5 ATP.</p> Signup and view all the answers

Explain the significance of proton neutralization by glutamate in the c unit of ATP synthase.

<p>Proton neutralization by glutamate in the c unit helps to trigger the rotation necessary for ATP synthesis.</p> Signup and view all the answers

What is the relationship between proton gradient and ATP synthesis in ATP synthase?

<p>The proton gradient drives the rotation of ATP synthase, which facilitates the synthesis and release of ATP.</p> Signup and view all the answers

What is the role of a weak acid and its conjugate base in a buffer solution?

<p>A weak acid and its conjugate base work together to resist changes in pH by neutralizing added acids or bases.</p> Signup and view all the answers

How does the Henderson-Hasselbalch equation relate to buffer solutions?

<p>The Henderson-Hasselbalch equation provides a mathematical relationship to calculate the pH of a buffer solution based on the concentration of the weak acid and its conjugate base.</p> Signup and view all the answers

What are diastereomers, and how do they differ from enantiomers?

<p>Diastereomers are stereoisomers that are not mirror images of each other, differing in the configuration of one or more but not all stereocenters, unlike enantiomers which are non-superimposable mirror images.</p> Signup and view all the answers

Describe how weak acids and weak bases are absorbed in the human body.

<p>Weak acids are primarily absorbed across the stomach, while weak bases are absorbed predominantly in the intestine.</p> Signup and view all the answers

What factors affect the rate of absorption of a drug?

<p>Factors such as the route of administration, dosage concentration, and lipid solubility influence the absorption rate of a drug.</p> Signup and view all the answers

Explain the significance of dipoles in molecular interactions.

<p>Dipoles result from uneven charge distribution within molecules, leading to polarity and affecting how molecules interact through forces like hydrogen bonding and London dispersion forces.</p> Signup and view all the answers

What does it mean for two molecules to have a permanent dipole?

<p>A permanent dipole indicates a consistent non-symmetrical charge distribution across a molecule, leading to stronger intermolecular attractions.</p> Signup and view all the answers

How do hydrogen bonds differ from ionic bonds?

<p>Hydrogen bonds are interactions between a hydrogen atom and a highly electronegative atom, while ionic bonds are electrostatic forces between positively and negatively charged ions.</p> Signup and view all the answers

What is thermodynamic temperature, and how is it measured?

<p>Thermodynamic temperature is an absolute measure of the average total internal energy of a system, typically measured in Kelvin (K).</p> Signup and view all the answers

What is the relationship between symmetry and melting points of molecules?

<p>Molecules with greater symmetry tend to have higher melting points due to better packing and increased order in the solid state.</p> Signup and view all the answers

Study Notes

Fundamentals of Chemistry

  • Atoms are the smallest particles with properties of a given element.
  • Atoms contain protons, neutrons, and electrons.
  • A unified mass unit is 1/12 the mass of a carbon-12 atom.
  • Atomic number (Z) is the arrangement of elements in the periodic table.
  • Ionization energy is the energy needed to remove a valence electron.
  • Electron affinity is the energy change when an electron is added.
  • Electronegativity is an atom's ability to attract electrons.
  • Atomic radius is the distance from the nucleus to the outermost electron shell.
  • Isotopes are variants of an element with different mass numbers (different number of neutrons).
  • Carbon has two stable isotopes: carbon-12 and carbon-13.
  • Nuclide symbols represent mass number on top and atomic number on bottom.
  • Rutherford-Bohr model describes positively charged nuclei surrounded by negatively charged electrons in specific orbits. It is not accurate for atoms with more than one electron.
  • Quantum mechanical model describes electrons as having wave-like properties and their behaviour following the Schrödinger wave equation.

Molecular Geometry

  • Wave function describes the probability of finding an electron at a particular point in space.
  • Atomic orbitals are regions of space with high probability of finding an electron.
  • Quantum numbers describe the size, shape, orientation, and properties of electrons(principal/shell/orbital/magnetic/spin)
  • Orbitals with the same energy are described as degenerate.
  • Aufbau principle: electrons fill the lowest energy orbitals first.
  • Hund's rule: electrons fill separate orbitals before pairing up in the same orbital.
  • Ionic bond: electron transfer to a more electronegative atom.
  • Covalent bond: sharing of electrons (less than one difference in electronegativity).
  • Polar covalent bond: Unequal sharing of electrons.
  • Structural formula: order of chemical groups.

Valence Bond theory

  • Overlap of atomic orbitals forms bonds.
  • Sigma bonds form end-to-end overlap.
  • Pi bonds form sideways overlap.
  • Hybridisation: new set of atomic orbitals.

Molecular Orbital theory

  • Molecular orbitals describe regions of space where electrons are likely to be found in molecules.

Moles & molar mass

  • Moles: number of discrete particles.
  • Avogadro's number is 6.022 × 10^23
  • Molar mass: mass of one mole of a substance.
  • Number of moles = mass/molar mass

Acids and bases

  • Water dissociates into H₃O⁺ and OH⁻.

  • Rate of disassociation = K₁ [AB]

  • Rate of association = K₂ [A][B]

  • At equilibrium, K₁[AB] = K₂ [A][B].

  • The dissociation constant (K) can be calculated.

  • lonic product of water Kw = [H⁺][OH⁻] = 1 X 10⁻¹⁴ M².

Biomolecular Bonding

  • Intermolecular forces: forces between molecules.
  • Dipoles: charge distributed across the molecule. Can cause polarity.
  • Permanent dipole interactions: non-symmetric distribution of charge.
  • London Dispersion forces: transient dipoles lead to attraction within/between molecules. Larger molecules mean stronger LDFs
  • Hydrogen Bonds: very electronegative atoms attract electron-deficient hydrogen.
  • Ionic bonds: electrostatic forces between oppositely charged groups.
  • Melting Points: Higher melting points result in better packing in solids and more symmetry.

Thermodynamic

  • Thermodynamics: the relative energies between reactants and products.
  • System: reactants and products.
  • Surroundings: everything else outside the system.
  • Boundary: where the two meet.
  • Total energy in an isolated system doesn’t change.
  • Total energy of system and surrounding won’t change.
  • Heat: energy per mole.
  • Enthalpy: total energy a chemical system possesses.
  • Kinetic energy: energy in the form of moving electrons, vibration of atoms, rotation/translation of molecules.
  • Chemical potential energy: covalent/ionic bonds.

Enzymes and Enzyme Kinetics

  • Enzymes catalyse biochemical reactions by lowering the energy required to reach the transition state.
  • Substrate binds to the active site forming an enzyme-substrate complex.
  • Enzyme-substrate complex undergoes a reaction then releases the product forming free enzyme. This interaction between the substrate and functional groups lowers the activation energy.
  • Reaction velocity v maximum at high substrate concentration. At low concentration of substrate reaction rate is directly proportional to substrate concentration.
  • Reaction velocity v is the maximum reaction rate when the enzyme is saturated, unaffected by changes in substrate concentration.
  • Reaction velocity depends on substrate concentration ([S], first order kinetics) at low concentrations, and maximum reaction velocity (Vmax) at high substrate concentrations(zero order kinetics).
  • Michaelis-Menten equation V = (Vmax[S])/(Km+[S])
  • Lineweaver-Burk plot can be used to determine Km(Michaelis constant).
  • KM is the substrate concentration at half of Vmax.
  • kcat (turnover number of the enzyme) = k2, max number of chemical conversions per second the enzyme will make.

Allosteric Effects and Regulation of Enzymes

  • Multi-subunit proteins respond to small changes in the substrate concentration.
  • Substrate binding at active site causes a change to the enzymes quaternary structure, affecting the reaction rate.
  • Allosteric binding of substrate can either inhibit or activate enzymes.
  • Inhibitors: molecules that reduce enzyme activity by binding allosteric sites and reducing active site activity.
  • Effectors/activators: molecules that cause conformational changes and increase the active site’s efficiency.

Glycolysis and Gluconeogenesis

  • Glycolysis: glucose to pyruvate; occurs in cytoplasm; 10 steps using enzymes
  • Gluconeogenesis: pyruvate to glucose; occurs in cytoplasm and mitochondria; takes place as it is the reversal of glycolysis.

Oxidative Phosphorylation

  • Pyruvate is converted to acetyl-CoA, reducing NAD+ to NADH and releasing CO₂ using pyruvate dehydrogenase complex.
  • Acetyl-CoA enters the citric acid cycle (TCA/Krebs).
  • Oxidation of Acetyl-CoA in the citric acid cycle removes CO2 and reduces electron carriers.
  • Electron carriers (e.g., NADH, FADH₂) pass electrons to the electron transport chain (ETC), generating a proton gradient.
  • This gradient is used to drive ATP synthesis through ATP synthase.

Other biochemical concepts

  • Protein purification: various methods used to isolate proteins.
  • Lipid aggregation: hydrophobic/hydrophilic properties of lipids drive the formation of micelles and bilayer membranes.
  • Nucleic acids: linear polymers of nucleotides containing coded information.
  • Monomeric nucleotides: molecules with functions like energy.
  • Amino acids: building blocks of proteins with central α–carbon atom connected to an amino group, carboxylic acid and side chain.
  • Proteins: long chains of amino acids.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

CBI Chemistry Notes PDF

Description

Test your knowledge on the fundamental concepts of chemistry, including atomic structure, isotopes, and the periodic table. This quiz covers essential topics related to atoms, their properties, and key terms like ionization energy and electronegativity. Challenge yourself to understand the basics of this vital science field.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser