Question

Which of the following would favor gluconeogenesis in the fasted state? A. Fructose 1,6 -bisphosphate stimulation of pyruvate kinase B. Acetyl CoA activation of pyruvate carboxylase C. Citrate activation of acetyl-CoA carboxylase D. Malonyl CoA inhibition of carnitine palmitoyltransferase I E. Fructose 2,6 -bisphosphate stimulation of 6 -phosphofructo-1-kinase

Short answer

Answer: B. Acetyl CoA activation of pyruvate carboxylase

Step-by-step solution

Understand the regulatory mechanisms of gluconeogenesis

During a fasted state, the process of gluconeogenesis takes place to help maintain blood glucose levels. Gluconeogenesis is regulated by allosteric enzymes that control the rate of the reactions. Some of these regulatory steps include the inhibition or activation of enzymes involved in the process.

Analyze each option

A. Fructose 1,6 -bisphosphate stimulation of pyruvate kinase: This step is a part of glycolysis and not gluconeogenesis. Therefore, it does not favor gluconeogenesis. B. Acetyl CoA activation of pyruvate carboxylase: Pyruvate carboxylase is an enzyme involved in the first step of gluconeogenesis, producing oxaloacetate from pyruvate. Acetyl CoA activation of pyruvate carboxylase promotes gluconeogenesis. C. Citrate activation of acetyl-CoA carboxylase: This step is involved in fatty acid synthesis and is not directly related to gluconeogenesis. It would not favor gluconeogenesis. D. Malonyl CoA inhibition of carnitine palmitoyltransferase I: This step is involved in the inhibition of fatty acid oxidation. It would not directly favor gluconeogenesis. E. Fructose 2,6 -bisphosphate stimulation of 6 -phosphofructo-1-kinase: This step is part of glycolysis regulation, and its stimulation would promote glycolysis instead of gluconeogenesis.

Select the correct answer

Based on our analysis of each option, we can conclude that option B (Acetyl CoA activation of pyruvate carboxylase) is the one that would favor gluconeogenesis in the fasted state.