Ans glyceradehyde 3 P Pi NAD 13 biphosphoglycerate ADP 13 biphosphoglycerate

Ans glyceradehyde 3 p pi nad 13 biphosphoglycerate

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Ans: glyceradehyde-3-P+ Pi+ NAD+ +1,3-biphosphoglycerate +ADP ----> 1,3- biphosphoglycerate + NADH +H^+ +3-biphosphoglycerate +ATP b)( 2 points ) What is the calculated free energy ∆G o ’of the combined reaction? ∆G= -10.9 kj/mol c) ( 3 points) What does the free energy tell us regarding whether the two coupled reaction moves forward? Ans: The reaction doesn’t favor the products strongly. Problem 3. (36 Points) Glycolysis/gluconeogenesis is regulated at rate limiting steps as shown in the diagram below. Glucose Enzyme 1Enzyme 2 Glucose-6P Fructose 6 P Enzyme 3Enzyme 4 Fructose 1, 6 BP Phosphoenol pyruvate (PEP) Enzyme 5Enzymes 6, 7 Pyruvate
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Figure 1. Glycolysis and gluconeogenesis 1. ( 14 Points ) At these rate limiting steps, separate enzymes are present for the forward and reverse reactions. Match the letter (a-g) of the enzymes listed below with the corresponding number (1-6) corresponding to the enzyme listed in Figure 1 above. Note- the number 6 is used twice, for enzymes that correspond to enzymes 6 or 7. Otherwise, each glucose reaction enzyme has 1 answer. a. Fructose 1,6 Bisphosphatase b. Pyruvate carboxylase c. Phosphofructokinase (PFK) d. Hexokinase e. Pyruvate kinase (PK) f. Glucose-6 Phosphatase g. Phosphoenolpyruvate carboxykinase (PEPCK) 1. Enzyme 1 Ans: D 2. Enzyme 2 Ans: C 3. Enzyme 3 Ans: A 4. Enzyme 4 Ans: G 5. Enzyme 5 Ans: B 6. Enzyme 6,7 Ans: E 2. ( 10 Points ) PFK and its counterpart in the reverse reaction are highly regulated enzymes. State below how PFK changes state (activated vs. repressed) due to these conditions. c. Increased ATP repressed b. Increased ADP Activated a. Increased AMP Activated e. Increased Fructose 2,6 Bisphosphate (F2,6 BP) Repressed d. Increased Citrate Repressed 3. ( 4 Points ) As discussed in class, The F2,6 BP is a potent controller both enzyme 3 and enzyme 4 listed in Figure 1, which has been rewritten below in Figure 2 to show separate reactions for F6P and F1,6 BP. The fates of F6P are shown, with reactions in orange (gluconeogenesis), blue (glycolysis), and importantly the formation of Fructose 2, 6 bisphophatase (F2,6 BP). F62BP is an extremely potent regulator of enzyme 3 and enzyme 4. F26BP is synthesized from a single enzyme that has multifunctional activity, including Phosphofructokinase (PFK2) and Fructose Bisphosphatase 3 (FBPase-2), and the reaction that it controls is shown in black arrows.
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Figure 2. Glycolysis and gluconeogenesis 4. ( 4 Points ) What is the effect of F26BP on Enzyme 3? What is the effect of F26BP on Enzyme 4? 5. ( 8 Points ) Figure 2 illustrates that at the rate limiting steps, gluconeogenesis is separate process than glycolysis rather than simply the reverse. Write T/F next to each statement below regarding gluconeogenesis compared to glycolysis. a. Energy charge regulates gluconeogenesis, but not glycolysis. Ans:False b. Control of glycolysis occurs at not a single, but at multiple rate limiting reactions. Ans: True c. Separate reaction steps enable reciprocal regulation of gluconeogenesis and glycolysis, which means the factors that promote one process also inhibit the opposing the process. Ans: True d. The rate limiting reactions of glycolysis are endergonic while the opposing the rate limiting processes in gluconeogenesis are exergonic as well Ans: True 6. ( 4 Points
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