Question

In an ATP synthase which has 12 copies of the c subunit, how many protons move through the enzyme for each one ATP that is synthesized? 44. 4 12. 45. An uncoupler acts by: a. Inhibiting a redox couple b. nhibiting proton pumping complexes. c. nhting oxygen reduction d. Collapsing the proton gradient e. Uncoupling the F and Fo subunits of the ATP synthase GLUCONEOGENESIS The reactions of glycolysis that are replaced by different enzymes in the gluconeogenesis pathway are those that: 46. a. Are substrate level phosphorylations. b. Are exergonic. c. Are endergonic. d. Produce ATP e. Consume ATP Fructose-2,6-bisphosphate is an allosteric effector that mediates reciprocal control of glycolysis and gluconeogenesis by activatingand inhibiting 47. b. Pyruvate kinase; pyruvate carboxylase. c. Pyruvate carboxylase; pyruvate kinase. d. Fructose-1,6-bisphosphatase; phosphofructokinase-1 e. Hexokinase; glucose-6-phosphatase.

Answer 1

44. C. (4) Each proton will rotate c subunit by 30 degree and for formation of 1 ATP we need to move gamma subunit by 120 degree. Hence 4 protons are required.

45. D. These act by disturbing the proton gradient formed so proton byepass the ATP synthase.

46. A. Substrate level phosphorylations

where fructose 1,6-bisphosphatase converts fructose 1,6-bisphosphate to fructose 6-phosphate, while in glycolysis, phosphofructokinase 1 converts Fructose-6-P and ATP to F-1,6-BisP and ADP. This is reverse glycolysis.

47. It activates fructose 1,6 bisphosphatase which will carry out gluconeogenesis and inhibiting phosphofructokinase-1 which is an enzyme of glycolysis, Since bisphosphate is already available.