8. Aerobic respiration of a 5 mM solution of tripeptide that is composed of the following three amino acids; alanine, leucine and isoleucine. Alanine breaks down to pyruvate, leucine breaks down to Acetyl-CoA and isoleucine breaks down to succinyl-CoA. Alanine NADH FADH2 OP ATP SLP ATP Total ATP Leucine Isoleucine Totals Show your work using dimensional analysis here: 4

Comparing Glycolysis Entry Points for Sucrose Sucrose can enter glycolysis by either of two routes: Sucrose phosphorylase: Sucrose + Pi fructose + glucose-1-phosphate Invertase: Sucrose + H20 fructose + glucose Would either of these reactions offer Jin advantage over the other In the preparation of hexoses fur entry into glycolysis?

How much ATP will be produced during the following metabolic scenario: Aerobic respiration of a 5mM lipid solution that is made up of one glycerol and an 8-carbon fatty acid and 12-carbon fatty acid. Recall that when glycerol breaks down to Glyceraldehyde-3-phosphate it costs one ATP but your get an extra FADH2. Every two carbons of a fatty acid break down to one acetyl-CoA. (pathways will be provided on the exam) Units cannot be entered in this style of question but the units of your answer should be in mM of ATP.

How much ATP will be produced during the following metabolic scenario: Aerobic respiration of a 5mM lipid solution that is made up of one glycerol and an 8-carbon fatty acid and 12-carbon fatty acid. Recall that when glycerol breaks down to Glyceraldehyde-3-phosphate it costs one ATP but your get an extra FADH2. Every two carbons of a fatty acid break down to one acetyl-CoA.  Units cannot be entered in this style of question but the units of your answer should be in mM of ATP.

Figure 27.3 illustrates the response of R (ATP-regenerating) and U (ATP-utilizing) enzymes to energy charge. a. Would hexokinase be an R enzyme or a U enzyme? Would glutamine: PRPP amidotransferase, the second enzyme in purine biosynthesis, be an R enzyme or a U enzyme? b. If energy charge = 0.5: Is the activity of hexokinase high or low? Is ribose-5-P pyrophosphokinase activity high or low? c. If energy charge = 0.95: Is the activity of hexokinase high or low? Is ribose-5-P pyrophosphokinase activity high or low?

Study Figure 19.18 and decide which of the following statements is false. Pyruvate dehydrogenase is inhibited by· NIADH. Pyruvate dehydrogenase is inhibited by AΤΡ. Citrate synthase is inhibited by NADH. Succinyl-CoA activates citrate synthase. Acetyl-CoA activates pyruvate carboxylase.

Explaining the Stoichiometry of Fatty Acid Synthesis Carefully count and account for each of the atoms and charges in the equations for the synthesis of palmitoyl-CoA, the synthesis of malonyl-CoA, and the overall reaction for the synthesis of palmitoyl-CoA from acetyl-CoA.

Distinguishing the Mechanisms of Class I and Class I Aldolases Fructose bisphosphate aldolase in animal muscle is a class 1 aldolase, which forms a Schiff base intermediate between substrate (for example. fructose-1, 6-bisphosphate or dihydroxyacetone phosphate) and a lysine at the active site (see Figure I8.12). The chemical evidence for this intermediate conies from studies with aldolase and the reducing agent sodium borohydride, NaBH4. Incubation of the enzyme with dihydroxyacetone phosphate and NaBH4 inactivates the enzyme. Interestingly, no inactivation is observed if NabH4 is added to the enzyme in the absence of substrate. Write a mechanism that explains these observations and provides evidence for the formation of a Schiff base intermediate in the aldolase reaction.

Understanding the Stoichiometry of Cholesterol Synthesis Write a Balanced, stoichiometric reaction for the synthesis of cholesterol from acetyl-CoA.

Ethanol as a Source of Metabolic Energy (Integrates with Chapters 19 and 20.) Acetate produced in ethanol metabolism can be transformed into acetyl-COA by the acetyl thiokinase reaction: Acetate+ATP+CoASHacetyleCoA+AMP+PPiAcetyle-CoA then can enter the citric acid cycle and undergo oxidation to 2 CO2by this route, assuming oxidative phosphorylation is part of the process? (Assume all reactions prior to acetyl-CoA entering the citric acid cycle occur outside the mitochondrion). Per carbon atom, which is a better metabolic fuel, ethanol or glucose? That is, how many ATP equivalents per carbon atom are generated by combustion of glucose versus ethanol to CO2?