BIOL 302 1st Edition Lecture 22Outline of Last Lecture I. Membrane transport pt 2Outline of Current Lecture I. Introduction to MetabolismII. ThermodynamicallyIII. equivaleCurrent LectureI. A thermodynamically unfavorable reaction must be coupled with a favorable reactionA. Because ΔG must be negative, biosynthetic and degradative pathways are always distincto’ + RT ln [[C][DA][B]] ATP ADP + PiΔG = ΔG II. Metabolism is a networkA. Carbon fuels are oxidized to yield energy (ATP) and reducing power (NADH, NADPH)B. Metabolism can be broken down into a relatively small number of types of reactions using a central set of common intermediates, including activated carriers.C. Metabolic pathways are highly regulated and interconnectedThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. Metabolism happens in a series of small stepsA. Whether degradation (catabolism) or synthesis (anabolism), complex pathways can be studied and explained as a series of simple stepsB. We’ll study the details of all the small steps to understand how pathways workC. describe carbohydrate catabolismD. Aerobic pathways are usually the most efficient (require O2)IV. Two phosphor-anhydride bonds = intermediate phosphoryl- transfer potentialA. ATP hydrolysis drives metabolism by shifting the equilibrium of coupled reactionsV. ATP is a central player in metabolismA. Why does ATP have such a high phosphoryl-group-transfer potential?1. Resonance Stabilizationa. Pi has more stable structures than the γ-phosphoryl group2. Electrostatic repulsiona. ATP’s triphosphate carries 4 negative charges at pH 7 – these repel each other. Repulsion is reduced when ATP is hydrolyzed.3. Stabilization due to hydrationa. More water can bind and stabilize ADP + Pi compared with ATP.VI. Many types of phosphates play roles in metabolismVII. Oxidation of carbon fuels yields energy and reducing equivalentVIII. Clicker Question: Which of these do you think has more reducing potential?A. GlucoseB. fatty acid IX. Catabolism of a wide variety of dietary fuels proceeds through only a few common intermediatesA. Stage 1: Digestion Partial hydrolysis to enable absorption; no energy capturedB. Stage 2: Degradation into common intermediates. Small amount of ATP madeC. Stage 3: Energy extracted. Acetyl CoA is completely oxidized (or stored as fat)X. Metabolic “carrier molecules”: FADHXI. Metabolic “carrier molecules”: Coenzyme A XII. Metabolism is full of different types of “carrier molecules”XIII. Frequently Recurring Reaction TypesA. Oxidation-Reduction Reactions Succinate DehydrogenaseB. (Citric Acid Cycle)C. Ligation ReactionsD. Pyruvate Carboxylase, GluconeogenesisXIV. Frequently Recurring Reaction TypesA. Isomerization ReactionsB. Aconitase (Citric Acid Cycle)C. Group Transfer ReactionsD. Phosphatase – dephosphorylatesE. Hexokinase (glycolysis)XV. Clicker Question: What’s the name of the enzyme that generates free glucose and Pifrom glucose-6-phosphate?A. glycerol kinaseB. glucose-6-phosphataseC. hexokinase D. pyruvate carboxylaseXVI. Clicker Question: What’s the product of a sulfatase?A. PO4B. H2OC. SO3D. SO4XVII. Frequently Recurring Reaction TypesA. Hydrolytic ReactionsB. General ProteaseC. Chemistry at Double BondsD. Enolase (glycolysis)XVIII. Enolases are important because they generate high-energy C=C bondsA. Enol (new Bonds)B. Conjugated C=C bonds can capture energy via resonance1. PolyeneXIX. Frequently-recurring Reaction IntermediatesA. Schiff Base (electron sink)XX. Metabolic processes are regulated in 3 principal waysA. The amounts of an enzymeB. Catalytic activityC. Accessibility of substratesXXI. Clicker Question: Which of the following is NOT a way in which enzyme activity can be regulated?A. denaturationB. phosphorylationC. localization within the cellD. binding of a competitive inhibitorE. All of the above are ways in which enzyme activity can be regulated XXII. Complex regulatory mechanismsA. allow the body to switch between catabolism and anabolism whenever necessaryXXIII. Endocrine mechanismsA. also contribute to metabolic