Question

Which of the following sequences of Krebs cycle reactions is correct?

• A. Cisaconitate $\rightarrow$ succinate $\rightarrow$ malate $\rightarrow$ fumarate
• B. Oxaloacetate $\rightarrow$ malate $\rightarrow$ succinate $\rightarrow$ fumarate
• C. Citrate $\rightarrow$ succinate $\rightarrow$ oxaloacetate $\rightarrow$ fumarate
• D. Oxalosuccinate $\rightarrow$ $\alpha$-ketoglutarate $\rightarrow$ succinyl Co-A $\rightarrow$ succinate

Hint:

Remember: {Oxalosuccinate → $\alpha$-ketoglutarate → Succinyl Co-A → Succinate}.

Answer 1

The Correct Option is D

Step 1: Overview of Krebs cycle.
The Krebs cycle is a series of enzyme-mediated reactions involved in aerobic respiration.
Step 2: Correct reaction sequence.
Oxalosuccinate is converted to $\alpha$-ketoglutarate, which is further converted into succinyl Co-A and then succinate.
Step 3: Verification.
Other options show incorrect order of intermediates and therefore are wrong.