Chapter 17, Problem 2E

Summary Introduction

To explain: Which round of the citric acid cycle will release labeled CO₂ if the methyl group of acetyl CoA is labeled with ¹⁴C.

Concept introduction: The pyruvate produced from the glycolysis can enter the citric acid cycle as acetyl CoA and splits into CO₂. If the methyl carbon of acetyl CoA is labeled with ¹⁴C, it becomes C3 of the succinyl of succinyl-CoA and appears at carbon 2 (C2) and carbon 3 (C3) positions of succinate, fumarate, malate, and oxaloacetate.