Why is citrate synthase a good candidate for a regulatory enzyme?
Site-directed mutagenesis techniques were used to synthesize a mutant citrate synthase enzyme in which the active site histidine was converted to an alanine. Why did the mutant citrate synthase enzyme exhibit decreased catalytic activity?
11. Which enzyme is NOT part of the TCA cycle? A. Citrate synthase B. Succinate dehydrogenase C. alpha-ketoglutarate dehydrogenase D. Aconitase E. Pyruvate dehydrogenase
Succinyl-CoA is a negative regulator of citrate synthase. Explain why this makes sense, and propose a possible mechanism for how this molecule inhibits citrate synthase. What other step of the citric acid cycle is inhibited by succinyl-CoA, and how do you expect that inhibition mechanism to be similar/different?
Which enzyme is NOT involved in the regulation of the citrate cycle? A) a-ketoglutarate dehydrogenase B) Succinate dehydrogenase C) Citrate synthase D) socitrate dehydrogenase
Acetyl COA + H2O Coo- o coo- Citrate synthase CH2 -OH -ooc— CH2 CH2 NADH + H+ COO- Oxaloacetate Coo- Citrate Aconitase Malate dehydrogenase NAD+ - Çoo- Çoo- ---OH -O00—-H HO-CH CH2 CH2 Coo- Malate Coo- Isocitrate Isocitrate lyase Malate synthase COO- COO- Coh CH2 Acetyl COA + H2O Ho Glyoxylate coo Succinate Figure 17.23 Biochemistry, Seventh Edition 2012 W. H. Freeman and Company Question 1 (10 pts) Using diagrams show the pathway that is used to convert succinate to...
the citric acid cycle has 8 enzymes: citrate synthase, aconitase, isocitrase dehydrogenase,.... 1 Jom L C Tegulation TCA cycle (Ch. 16) 1. The citric acid cycle has eight enzymes: citrate synthase, aconitase, isocitrate dehydrogenase, a-ketoglutarate dehydrogenase, succinyl-CoA synthetase, succinate dehydrogenase, fumarase, and malate dehydrogenase. (a) Write a balanced equation for the reaction catalyzed by each enzyme. (b) Name the cofactor(s) required by each enzyme reaction. (c) For each enzyme determine which of the following describes the type of reaction(s) catalyzed:...
d) e) f) Could 2,2,2-trifluoroacetyl CoA be processed by citrate synthase? Could 2-fluoroacetyl CoA be processed by citrate synthase? What is the mechanism of citrate synthase?
3. (10 pts) Citrate synthase catalyzes the reaction: Oxaloacetate + acetyl – COA → citrate + HS – COA The standard free energy change for the reation is -31.5 k] . mol-1. a) Calculate the equilibrium constant for this reaction at 37°C. b) Would you expect this reaction to serve as a control point for its pathway (the citric acid cycle)?
PEK-1 is an enzyme that catalyzes step 3 of glycolysis. The activity of this enzyme is regulated in the following ways: O either ADP or ATP can bind a particular regulatory site on this allosteric enzyme. O if ATP is bound to the regulatory site, the enzyme's activity rate increases. if ADP is bound to the regulatory site, the enzyme's activity rate increase. high levels of citrate indicate that the CAC is not keeping up, citrate binds to the regulatory...
Is ATP-citrate lyase (citrate cleavage enzyme, CCE) necessary for de novo synthesis of palmitate (C-16:0) from glycerol in your liver? __yes or no_____ Why?