Chemistry of Life Before Wrap Up 2 PDF
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University of New Haven
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This document discusses enzymes, biological catalysts that speed up chemical reactions. It explains how enzymes assist in metabolic pathways, making reactions start with less energy required. It also details enzyme characteristics, factors influencing enzyme activity, regulation of enzyme activity, and energy concepts like kinetic energy, potential energy, and Gibbs Free Energy. In addition to this, it covers topics including metabolism as a collection of orderly, enzyme-mediated reactions and the role of ATP in energy coupling related to catabolic and anabolic pathways.
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After Wrap Up I Before Wrap Up 2 Enzymes Biological Catalysts · · Speed up chemical reactions A mumB C num D M 2...
After Wrap Up I Before Wrap Up 2 Enzymes Biological Catalysts · · Speed up chemical reactions A mumB C num D M 2 Transition Site e A - B ↑ PAGO i C D ~ Progress of the reproducts 7 assist in metabolic pathways · · help make reactions start so that less energy is required · proteins that speed up chemical reactions · enzymes make chemical reactions more likely to happen · don't make reactions happen that wouldn't have happened otherwise · make reactions cheaper to run push reactants up the hill until they reach · an energy state high enough that the bonds begin to break-transition state Transition State : point in which we transition fromneedingtoputenergyintothe on reaction Ea energy of activation = ↳ happens at transition state in bond represents it being ready to break ~ · Reactants energy> than products = Exothermic · Products energy , than reactants Endothermic = Enzymes speed up a reaction by lowering Ea 1 Course of reaction or Progress of the reaction Products ( a get products faster · want to the benefit with minimal effort get · Characteristics of Enzymes · do not create reactions · not altered or use up by reaction (recycled · substrate specific (specific to reaction type) · function is based on 3-dimensional shape mostly proteins ! · ↳ if something is wrong with shape it functionality maybe to point where it can't do its job # of diseases and malfunctions and cellular processes that are related to enzyme malfunction and absence of certain enzymes ↳ Lactose intolerance : lactose sugar that's in milk. Without proper enzyme Dactase) body is reallybadatbreakdown acta · A key function of enzymes is their ability to bind their substrates with high specificity. This is due to the structure of the enzyme's active site * Substrate it's : thing working on ↳ interacts to help the reaction go Enzyme mode of action enzyme structure ensures specificity of function ·. The substrate sucrose , consists of 1 , glucose active sites Where and fructose bonded together (infoldings) work happens. The 2 substrate binds active site of the to the enzyme forming and enzyme-substrate complex , water is added in. The binding of the substrate and enzyme 3 places stress on the glucose-fructose bond, and the bond breaks. Products are released and the enzyme is 4 , free to bind other substrates * enzyme not used up ! It can cycle back and be used again degrade over time - > can Factors influencing level of enzyme activity ~ enzyme is less active temperature (sweet spot) * Core over extremities · · DH · substrate concentration ↳ Concentration then rate i PH · pepsin-optimal activity at acid pH typical cellular enzyme optimal activity at neutral · = PH · Trypsin = optimal activity at basic pH Regulation of enzyme activity cells regulate metabolism by regulating enzymes · · Genes producing enzymes can be turned on or off to regulate enzyme production be made to Changes can existing enzyme · Structure to increase decrease function or · Allosteric effection cofactors and coenzymes · assist With the enzymatic reaction ; may be inorganic ions or nonprotein organic molecules NAD + · FAD · NADP + · Competitive and noncompetitive inhibition · competitive inhibitor blocks where substrate = wants to bind to active site · doesn't block inhibitor binds noncompetitive = , somewhere else-not active sites change active site shape - Feedback Inhibition · end product is on enzyme I · doesn't show intermediates Living Organisms maintain homeostasis · Feedback inhibition prevents the formation of too much product of a metabolic pathway Energy Kinetic energy (movement) · Potential energy llocation) · - a diver has more potential energy on the platform than in the water - diving converts potential energy toKinetic energy Climbing up converts the Kinetic energy of - muscle movement to potential energy · Energy transfers are subject to laws of thermodynamics System · Surroundings · · The quantity of energy in the universe is constant , but the quality is not Solar < chemical > mechanical Gibbs Free Energy (G) energy available to do work · change in free energy (DG) · spontaneous reactions · decrease free energy in a system · negative AG in system - increases entropy in surroundings Exergonic Reaction · Catabolic (decomposition) Products have less free energy than the · reactants net loss of free (-DG) from system energy · · Spontaneous · release free energy (-AG) - ndergonic Reaction · Anabolic (synthesis) products have free than the more energy · reactants · requires energy input (+AG) to system · not spontaneous consumes free energy (+AG) · mmmcroducts F · Mo Y ergy released (a) ExeProgress ofthereactionenergy released 1 Products reactants (b) mmmmmmm e Progress of the reaction > 7 endergonic reaction : energy required Metabolism - all chemical reactions orderly : can't skip ahead · orderly enzyme-mediated reactions and can't go backwards Start point is the Step by step or cyclic pathways · end point · ATP most common energy coupling molecule Catabolic pathways < Anabolic pathways All chemical reactions have a specific ↑ · Energy of Activation (a) · taking things apart to build something new out of those parts · ATP provides energy for cellular work mechanical (to movel · transport (cell membrane) · Chemical (take reactants and make · products) · Adenosine triphosphate (ATP) · RNA nucleotide with unstable phosphate bonds adenine + N - C = O L 90 N Hc - I -0 - pro - p - o - 0 - CH2 N- 2 N= Ch o o- Fi H H Phosphate group OH OH ribose Oxidated phosphorylation in the Mitochondria · ATP Synthesis involves phosphorylation Endergonic · · Phosphate groups are hydrolyzed to release energy · Exergonic H20 7 ATP + me m Energy for Energy from L cellular work catabolism ADP + Pi Cendergonic , lexergonic energy-consuming energy-releasing processes) processes) ATP is a common energy coupling mechanism glucose 7 A- PvPvP exergonic endergonic -Protein (glucose CATP synthesis) breakdown) exergonic endergonic CATP breakdown) (protein L Synthesis) CO2 +20 +heat A - P-D + p aming acids Cellular Metabolism cellular respiration S · · fermentation z Catabolic pathways that yield energy by oxidizing organic fuels · Breakdown of organic molecules is exergonic cellular respiration a releasing energy · - Aerobic (requires O2) from bonds · Fermentation Anaerobic - Redox Reactions : Oxidation and Reduction · Transfer of electrons releases energy to Synthesize ATP Oxidation lose electrons, or is oxidized I · - · Reduction- gain electrons or is reduced , positive reducing charge - oxidized- Xe + Y > X + Ye- - reduced Oxidation i Oss eduction S air · During cellular respiration , fuel (such as glucose is oxidized , and O2 is reduced Hydrogen gets extra 7 electrons becomes oxidized ~ Cotti206 + 102 < GCO2 + GHz0 + Energy breakso becomes reduced many as electrons can't just around hang so they · are transferred molecules down organic are broken in a · series of steps (H--Lenergy) electrons from food -- 2H + + 1202 = Hz0 to produce energy released for ATP Synthesis Substrate level phosphorylation - Direct transfer of phosphate Oxidative phosphorylation Electron transport and electrogenic - proton pump (chemiosmosis) The Stages of Cellular Respiration cellularrespiration has four stages · - Glycolysis (breaks down glucose into two moleculesOfPvtecarbonmocetedintomitochondria enzymei - The Citric Acid Cycle (Kreps Cycle) (completes the breakdown of pyruvates - Oxidative phosphorylation (Electron transport chain) (accounts for most of ATP synthesis) Oxidizing and adding phosphates ↳ with or without * Stages 2-4 in the mitochondria < outside mitochondria I Glycolysis in cell Glucose NADH + S P Pyruvate -electron V s Pyruvate NADH S Oxidation > CO2 I Acetyl-CoA Kreb ↳ Keeps V cycle going NADH > CO2 Krebs > - in mana > - electron Shutteof intermediatesta Cycle matrix #ADH2 < deenergized versions NADTFAD O2 H2O e- V nN V M H+ ~ e- Electron e- Chemiosmos is Transport Chain Y ATP Synthase Getting water e-to flow to do work-waterwheel through chain to create some · power pumping of H from + energy to mitochondrial matrix to intermembrane space ↳ thenfall through ATP synthase Synthasize or build ATP - -fall powered by H+ through down gradient they turn enzyme and it reconstructs ATP from ADP-chemiosmosis C · 8 O : ·S S 8 S · e ↳- S -- & & n =& I B F J 27 T & G ↳ · · · & L - I I & · &: · sG · · 3 · · * 5 S # & & ↓ J · · & · ·S · 3 H" falls through ATP synthase which pushes on the complex complex rotate makes the pinwheel more Ht Spins faster ↳ - = as it rotates it grabs ADP and phosphate to Jam them together NADH drops electrons off in electron transport chain · Etc moves electrons in a series of steps - Each carrier in the chain is more and more electronegative - The energy released is used indirectly to synthesize ATP ATP Synthesis · free energy used to phosphorylate ADP forms ATP What if there is no oxygen ? Glycolysis can produce ATP with or without · 8 2 (in derobic or anaerobic conditions) · Fermentation Fermentation · used by organisms that can't respire - lack of suitable electron acceptor or lack of electron transport chain partial oxidation of glucose - · NADH oxidized back to NAD+ uses organic compound as terminal · electron acceptor - Typical pyruvate or derivative Lactate Fermentation Glucose ADD + Pi B - NADH + NAD HT CH3 CHE Ho- H - - COO- Pyruvate Lactate Alcoholic Fermentation Glucose + ADD + P: NAD n * NADH - + H+ PH3 - C coo- = Pyruvate 0 CO2 a Acetaldehyde I CH3 H Ethyl alcohol 300 · · · , · - ·E ↳ · · & S S s % 8 ! · s Mitochondrion Cytoplasm - - · ⑤ I ·T -L · & & · Electron Transport Chain · Photosynthesis my light m mmr n CO2 + H2@ mone produce Cellular is done to Photosynthesis andSo a cel organicmolecules occurs producing The cellular respiration are necessary for CO2 and 20 which Photosynthesis · Life powered is solar · Photosynthesis - converts solar energy into chemical energy · Autotrophs are the producers of the biosphere · Photoautotrophs · Photosynthetic organisms a) plants b) multicellular alga c) unicellular protist 6) cyanobacteria e) purple sulfur bacteria · Heterotrophs are the consumers of the biosphere Typically depend on photoautotrophs for food - and 02 Plant Leaf Morphology 7) some structure evolved to absorb sunlight · Leaves are area for photosynthesis - half a million chloroplasts per square mm - color of leaf is from Chlorophyll · Chloroplasts found mainly in mesophyll - cells densely packed with chloroplasts - Typical 30-40 per cell · Have high surface area so they act as photosynthetic arrays wide and thin-job is to absorb sunlight · to power photosynthesis · organs-composed of leaves are & +issues (layers of cells) mesophyll middle = · CO2 and O2 enters and exits through Stomata - open/close state controllable by plant · H20 enters through roots reaches leaves through network of veins - veins export sugar to roots and other - non-photosynthetic parts of the plant * both chloroplasts for plants have photosynthesis and mitochondria for cellular respiration · have multiple membranes because chloroplasts - they were once free living organisms (bacterium that already had its own membrane that was engulfed by another organism (eating) ↳ deposited another membrane Endosymbiotic Theory Thylakoid-cookie shaped sacks in stacked structure called granum (lumen empty) = ↳ where photosynthesis is happening · stroma = space around thylakoids · chemical equation for photosynthesis GCO2 + 12H20 + light 1Cotti20b + RO2 + 6H2O chemical of cellular change is reverse · respiration · Endergonic redox process - H2O is oxidized to O2 and CO2 is reduced to glucose * Goal is to make sugar for food or structure * Oxidizing water to oxygen and reducing CO2 with it to Ob < more energy associated 2. stages of photosynthesis reaction · Light - light energy converted to ATP NADH reducing power (sent to Calvin Cycle) - - thylakoid membranes transporte- · Calvin Cycle (light independent reaction) ATP and NADPH from light reaction is used - to fix carbon Goal = CO2 - > Glucose Stroma - H20 CO2 · · ⑧ Light Thylakoid · membrane T · T · I Chloroplast ·re 02 · Light is electromagnetic energy or radiation · electromagnetic spectrum - 380 to 750nm visible light spectrum - - travels in rhythmic waves but consists of discrete particles , called photons - fixed quantity of energy · Pigments absorb visible light make ATP through same process as cell respiration · Hydrogen ion gradient ATP Synthase Dropped through · · Spins to produce ATP Stoma/Stomata = CO2 and O2 in and out through openings e- Excitea M #He · * F photon I Photon -Ground (fluorescence) trophyllmolecule state a) Excitation of isolated Chlorophyll molecule Light absorption light energy causes electrons to get excited · - Move to higher energy shell - Unstable State Fall back to stable ground state - ↳ heat and photon (fluorescence) released · Pigments are organized into photosystems in thylakoid membrane Light harvesting complexes proteins with · = suspended chlorophyll molecules that can absorb the photons of light energy. Energy is handed off until it gets to paired Chlorophyll A molecules. Energizes an electron that jumps up to the primary electron acceptor found in the reaction-center complex. ↳ doesn't let it fall back down Two photosystems (11 - > 1) - Photosystem 1 (P700) - replacement e- from PSI wavelengths of 700nm (far-red) absorbs · Photosystem 11 (P680) replacement from H20 - - - · absorption peaks at 680 nm (also red part) Light drives the Synthesis of NADPH and ATP · key - energyto transformation is flow of electrons through photosystems May be non-cyclic or cyclic electron flow - * Primarily non-cyclic * water is oxidized - provides electrons ) why O2 is produced ↳ · goes to an electron transport chain between photosystems provides energy to regenerate ATP · sticks electrons on NADP + to regenerate NADPH Need Ht Stick on hydrogen then stick.. hydrogen on NADP + * non-cyclic = one direction (linear) · electrons travel down chain to PTOO get energized to primary acceptor but sometimes it hands a few high energy electrons off to an intermediate acceptor that will dump it into chain to get more energy to power the production of a little more ATP ↳ cyclic = cycle backwards * + membrane into thylakoid pump H across membrane to create a gradient so It can be pumped through ATP Synthase The Calvin Cycle · Cyclic and occurs in Stroma Builds molecules organic · - carbon dioxide from air fixed into sugar - consumes ATP and NADPH from light reaction · three phases - Carbon fixation (catalyzed by rubisco) - Reduction - Regeneration of the CO2 acceptor (RuBP) · Consumes three molecules of CO2 to produce one molecule of glyceraldehyde 3-phosphate (63P) used to make glucose and other organic - compounds · Requires ATP and NADPH to power cycle - from light reaction Phase 1 : Carbon fixation CO2 is incorporated into an organic molecule · via rubisco Phase 2 : Reduction and Carbohydrate production · ATP is used as a source of energy , and NADPH donates high-energy electrons Phase 3 : Regeneration of RuBP Two G3P are used to · make glucose andother 10 G34 are needed to Sugars ; the remaining RuBP via several enzymes ATP is regenerate. required for RuBP regeneration ↳ ribulose bisphosphate Input 6XCO2 biscot ~ 6 xRuBp cccc in so GADPGY C 12 X 1,3 BPG p Cc C i ↓ 12 NADPH 12 NADP + 12 xG3pY12p : I cc C 10 x G3P CCC 2x63P C Breaking Down Photosynthesis Stages 6 CO2 + 12H20 + light Sugar H20 02 4 con source of elections - from stripping Source of carbon H2O of electrons and H fixed into molecules organic * water > O2 light dependent reactions Calvin Cycle light ATP ATP > 3 + sugar ↑ t H20 NADPH NADPH ↑ t t from NADP + 02 CUz