NBEO Biochemistry Practice Exam

The compound that is crucial for the Krebs cycle to proceed following glycolysis is Acetyl CoA. After glycolysis, which breaks down glucose into pyruvate, pyruvate must be converted into Acetyl CoA before entering the Krebs cycle (also known as the citric acid cycle or TCA cycle). This conversion occurs through the action of the pyruvate dehydrogenase complex, which decarboxylates pyruvate, releasing carbon dioxide and reducing NAD+ to NADH in the process.

Acetyl CoA then combines with oxaloacetate to form citrate, marking the beginning of the Krebs cycle. This cycle is essential for the aerobic production of ATP, as it generates electron carriers like NADH and FADH2 that are utilized in the electron transport chain to produce ATP. Therefore, without Acetyl CoA, the Krebs cycle cannot initiate, highlighting its crucial role in cellular respiration following glycolysis.