Question

From what you know about step 2 of the citric acid cycle, rearrangement/dehydration, this step most likely occurs during a specific phase or condition. Explain when and under what circumstances the rearrangement/dehydration step of the citric acid cycle is likely to take place, and discuss its significance in the overall process of cellular respiration.

Answer 1

The rearrangement/dehydration step in step 2 of the citric acid cycle takes place under aerobic conditions in the mitochondrial matrix and is crucial for the further oxidation of metabolites, aiding in the production of ATP, NADH, and FADH2.

Step-by-step explanation:

The rearrangement/dehydration step of the citric acid cycle is step 2, where citrate is converted into its isomer, isocitrate. This step typically takes place in the matrix of the mitochondria, a condition that is rich in the necessary enzymes for the cycle.

It occurs under aerobic conditions since the continuation of the cycle is dependent on the transfer of electrons produced during the cycle to the electron transport chain, where oxygen is used. The significance of this step, and others in the citric acid cycle, lies in the further oxidation of metabolites, contributing to the production of CO₂, substrate level synthesis of ATP/GTP, and the generation of NADH and FADH₂, which are critical for oxidative phosphorylation and the production of a significant amount of ATP.