Citric acid cycle or Kreb's cycle is one of the fundamental steps of chemical reactions of aerobic/cellular respiration. It takes place in mitochondria. It generates high energy molecules and provides many intermediate products which are the substrate for other metabolic pathways. Therefore tight regulation of cycle is a very important phenomenon otherwise continuous generation of high energy molecules and byproducts are not good for cells.
acetyl-CoA COA The reactions of the citric acid cycle are shown in the image. As labeled...
not sure about reaction 3 and 4 acetyl-CoA COA The reactions of the citric acid cycle are shown in the figure Reactions 1, 3, and 4 are regulation points in the citric acid cycle. 1 citrate oxaloacetate 1 synthase citrate NADH + NAD malate dehydrogenase aconitase 2 malate Which of the molecules inhibits reaction 1? Isocitrate HO 17 fumarase NAD socitrate 3 dehydrogenase S D NADP ADP ОАТР O citrate synthase fumarate FADHI succinate co-ketoglutarate dehydrogenase ci-ketoglutarate NAD dehydrogenase +...
Part B Use the structures given in the cycle shown before this part identify the enzymes involved in each step of the citric acid cycle by completing each sentence Match the words in the left column to the appropriate blanks in the sentences on the right. View Available Hint(s) Reset Help isocitrate dehydrogenase aconitase citrate synthase fumarate hydratase succinate dehydrogenase succinyl-CoA synthetase a-ketoglutarate dehydrogenase malate dehydrogenase In step 1, oxaloacetate condenses with acetyl-CoA to form citrate, which is catalyzed by...
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:...
1. The enzyme responsible for the substrate level phosphorylation in the citric acid cycle is: a succinate dehydrogenase b. a-ketoglutarate dehydrogenase c. succinyl thiokinase d. isocitrate dehydrogenase e. aconitase 2. Which of the listed enzymes of the TCA cycle does not represent a regulatory enzyme?: a. isocitrate dehydrogenase b. succinate dehydrogenase c. malate dehydrogenase d. a-ketoglutarate dehydrogenase complex e. citrate synthase 3. Oxidative decarboxylation of pyruvic acid is regulated by: a. cyclic AMP-dependent mechanism b. cyclic AMP-independent mechanism 4. The...
Which of the following citric acid cycle enzymes lead to the formation of NADH and are regulatory enzymes? Isocitrate dehydrogenase Succinyl-CoA synthetase Succinate dehydrogenase Malate dehydrogenase • Citrate synthase
6. In mammals, which of the following does not occur during the citric acid cycle? A) formation of a-ketoglutarate. D) metabolism of acetate to carbon dioxide and water. B) net synthesis of oxaloacetate from acetyl-CoA. E) oxidation of acetyl-CoA. C) generation of NADH and FADHz. 7. Which of the following reaction generates GTP(ATP) in the CAC? A) Isocitrate to a-ketoglutarate. D) Fumarate to Malate. B) Malate to Oxaloacetate. E) Succinyl-CoA to Succinate. C) a-ketoglutarate to Succinyl-CoA.
Assume a cell has just completed glycolysis and the resulting pyruvate has a c-14 radio label on carbon -1. Highlight the carbon on the attached pages as it passes through the PDH complex and the TCA cycle until it is lost as CO2. If only a portion of the carbons are lost stop highlighting when the CO2 first starts to come off. ONLY ONE TIME THRU THE CYCLE ON EACH PAGE 2. Repeat question 1 but now assume the radio...
15. Genetic defect in pyruvate dehydrogenase complex lead a. maple syrup urine disease b. phenyike d. lactic acidemia e. pellagra syrup urine disease b, phenylketonuria c. galactosemia 10. Chemical modification by phosphorylation of pyruvate dehydros a. deactivates the enzyme b. activates the enzyme lation of pyruvate dehydrogenase complex : 17. Pyruvate carboxylase is positively ated through the allosteric mechanism by : a. ATP b. NADH c. Acetyl-SCOA d. TPP e. Biotin 18. Which of the listed coenzymes does not particip...
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...
9. Which of the listed enzymes of the TCA cycle is regulated by phosphorylation/dephosphorylation cycle ? : a. isocitrate dehydrogenase b. succinate dehydrogenase c. malate dehydrogenase d. a-ketoglutarate dehydrogenase complex e. citrate synthase 10. Name the enzyme catalyzing the following reaction: COOH + GTP - PEP + CO2 + GDP C=0 CH2 COOH a. PEP carboxykinase b. pyruvate kinase d. pyruvate carboxylase c. malic enzyme 11. Name the enzyme that catalyzes the reaction: glyoxylate + CH3CO-SCOA -- → malate +...