2. The enzyme exists in two interconvertible forms that differ markedly in their activities: Protomer (inactive) filamentous polymer (active) Citrate and isocitrate bind preferentially to the filamentous form, and palmitoyl-CoA binds preferentially to the protomer. Select the true statements that explain how these properties are consistent with the regulatory role of acetyl-CoA carboxylase in the biosynthesis of fatty acids. High citrate and isocitrate levels indicate that there is plenty of ATP, reduced pyridine nucleotides, and acetyl-CoA for fatty acid synthesis. Palmitoyl-CoA is a feedback inhibitor, driving the equilibrium in the direction of the inactive (protomer) form. Palmitoyl-CoA triggers phosphorylation to inactivate the enzyme. Citrate and isocitrate are the precursors for acetyl-CoA synthesis in the mitochondria, thus providing the starting material for fatty acid biosynthesis. The protomer and filamentous polymer are the two subunits of acetyl-CoA carboxylase that hold the biotin carrier protein, which rotates between the subunits depending on which compound is bound.

2. The enzyme exists in two interconvertible forms that differ markedly in their activities: Protomer (inactive) filamentous polymer (active) Citrate and isocitrate bind preferentially to the filamentous form, and palmitoyl-CoA binds preferentially to the protomer. Select the true statements that explain how these properties are consistent with the regulatory role of acetyl-CoA carboxylase in the biosynthesis of fatty acids. High citrate and isocitrate levels indicate that there is plenty of ATP, reduced pyridine nucleotides, and acetyl-CoA for fatty acid synthesis. Palmitoyl-CoA is a feedback inhibitor, driving the equilibrium in the direction of the inactive (protomer) form. Palmitoyl-CoA triggers phosphorylation to inactivate the enzyme. Citrate and isocitrate are the precursors for acetyl-CoA synthesis in the mitochondria, thus providing the starting material for fatty acid biosynthesis. The protomer and filamentous polymer are the two subunits of acetyl-CoA carboxylase that hold the biotin carrier protein, which rotates between the subunits depending on which compound is bound.

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter26: Synthesis And Degradation Of Nucleotides

Section: Chapter Questions

Problem 9P

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