Question

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 coenzymes does not participate in the oxidative decarboxylation of pyruvate? a. NAD+. b. lipoamide c. Coenzyme A. d. pyridoxal phosphate e. the pyrophosphate 19. Which among the listed molecules is the first com among the listed molecules is the first compound oxidized in the TCA cycles valoacetate. b. malate. c.aconitase. d. a-ketoglutarate e. social 20. Which of the listed enzymes of the TCA cycle is inhibited by ATP? Citrate synthase, b. isocitrate dehydrogenase c . -ketoglutarate dehydrogenase d. succinyl-CoA synthase e. malate dehydrogenase 21. Which of the listed amino acids narticinate in the transfer of a phosphate group in the reaction catalyzed by succinyl-CoA synthase? a. aspartate. b. glutamate. c. histidine. d. lysine. e. serine 22. Which of the following causes pyruvate dehydrogenase kinase to catalyze the phosphorylation and inactivation of the El in the pyruvate dehydrogenase complex? a elevated concentration of NADH and ATP. b. elevated concentration of NAD+. and ADP. c. Ca2+ d. insulin. e. elevated concentration of acetyl-CoA 23. Name the enzyme catalyzing the reaction: Isocitrate → succinate. + glyoxylate a. Isocitrate dehydrogenase. b. isocitrtae lyase. glyoxylate synthase. e. isocitrtae isomerase c. succinate synthase. d. 24. Which is the original source of carbohydrates in the developing seeds? a. citrate b. oxaloacetate c. succinate d . isocitrate e malate

Answer 1

23.Ans is (b)Isocitrate lyase. Isocitrate lyse catalise the conversion of isocitrate into succinate and glyoxylate.

24.Ans (e) malate is the source of carbohydrate.

20.Ans(c) Alpha keto glutarate dehydrogenase.

19 Ans(C) isocitrate.

18Ans (d) pyridoxal phosphate.

16(B)activates the enzyme.

15Ans(D)LActic acedemia

17Ans(C) acetyl -sCoa

21Ans(C)Histidine