(b) ☐ The exergonic reactions catalyzed by isocitrate dehydrogenase (ICDH) and α- ketoglutarate dehydroge-nase (aKGDH) are regu- lated by metabolites, in addition to the reaction catalyzed by citrate synthase. The diagram to the right illustrates the activity of ICDH (A,▲) and aKGDH (O,●) in the presence of 1.5 mM ADP (O,A) or 1.5 mM ATP (●,▲). In muscle tissue contraction of sarcomeres initiated by a nerve im- pulse results first in the release of Ca 2+ from the sarcoplasmic reticulum. As indicated by the chang- es in velocity of the two enzymes, what are the flux changes of the TCA cycle in muscle tissue upon release of Ca2+ under the influence of ADP viz. ATP and under the influence of NAD+ viz. NADH on cit- rate synthase? 100 75 Stimulation of activity (% of maximum) ŏ 25 1. -8 -7 -6 log {[Ca2+] (M)}

The Effect of lodoacetic Acid on the Glyceraldehyde-3-P Dehydrogenase Reaction (Integrates with Chapters 4 and 14.) How might iodoacetic acid affect the glyceraldehydes-3-phosphate dehydrogenase reaction in glycolysis? Justify your answer.

The reaction catalyzed by malate dehydrogenase has a ΔG°′ value of +29.7 kJ⋅mol−1. Given what this says about the occurrence of the reaction catalyzed by malate dehydrogenase in cells explain how the reaction catalyzed by citrate synthase (−31.5 kJ⋅mol−1) influences that activity of malate dehydrogenase. In addition, explain how the activity of citrate synthase functions as a regulatory point for the citric acid cycle

Compare and contrast Pyruvate Dehydrogenase with a-ketoglutarate dehydrogenaseOutline the mechanisms of both enzymes. Discuss the functions of the coenzymes. List the similarities and the differences between the 2 enzymes. Both are very large membrane bound complexes. What are the advantages of this strategy?How detailed is the enzyme structure known below(It's  Pyruvate Dehydrogenase )? What insight(s) does this structural detail give you about the enzyme mechanism.

Draw the products of the reaction of xylulose-5-phosphate and erythrose-4-phosphate catalyzed by transketolase in the pentose phosphate pathway. Provide the structure in the protonation state found in physiological conditions. H H H OH FO HO-H H-OH H OPO3²- Q transketolase Draw glyceraldehyde-3- phosphate H H- H H H O OH OH OPO3²- Draw fructose-6- phosphate Q I I

which statements are false?

The oxidation of Gly-3-P to 1,3-bisphosphoglycerate proceeds with an unfavorable AG which equals 6.3 KJ/mol, yet the flow through this point in the glycolytic pathway proceeds smoothly. Why???

[AktivGrid] Draw the product of the reaction of isocitrate catalyzed by isocitrate dehydrogenase in the TCA (citric acid) cycle. Provide the structure in the protonation state found in physiological conditions. 9 H-C-OH 800- -H CH₂ ° Coo of NAD+ dehydrogen isocitrate ase NADH, H*, Drawing CO2

2. (a) ( In contrast to the pyruvate dehydrogen- ase complex, the a-ketoglutarate dehydrogenase (aKGDH) complex is not up- or downregulated by phosphorylation or dephosphorylation. However, the complex exhibits cooperativity modulated by the presence of ADP, ATP, inorganic phosphate (Pi), and Ca2+, as illustrated by the diagram on the right for the bovine kidney enzyme complex. Note in the diagram how the addition of 10 μM Ca2+ shifts the affinity of the enzyme complex for aKG from 20 mM Pi/-Ca2+ to 20 mM Pi/+Ca2+. Calcium especially en- hances the cooperative influence of ADP and ATP. Using the expanded copy of the diagram at the end of the problem set, estimate the change in S0.5 (re- member that for allosteric enzymes S0.5 corresponds to KM of a nonallosteric enzyme) for the enzyme complex in the presence of 20 mM Pi/-Ca2+ and in the presence of 20 mM Pi/+Ca2+. Compare similarly the change in S0.5 for the enzyme in the presence of 20 mM Pi/-Ca2+ plus 1.6 mM ADP to the enzyme in the…

1) Sketch out the schematic diagram for the enzymatic mechanism of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) Please provide the structure of the functional groups of the substrate and enzyme involved in the reaction at each step (rest of the structure can be indicated as R) Indicate clearly the flow of the electrons at each step Indicate in short form the cofactor involved and the acid or basic groups of the enzyme involved