Which of the following compounds is considered to play the catalytic role in citric acid cycle?

The correct answer is: Oxaloacetate

• The catalyst for the eight processes that make up the citric acid cycle is a tiny molecule called oxaloacetate.
• Oxaloacetate gives an acetyl group, which is then entirely broken apart in eight stages to restore the oxaloacetate molecule for the next cycle. It's not really that simple, in a biological twist.
• You would believe that the enzymes might easily remove the two carbon atoms from the acetyl group by using the oxaloacetate as a convenient carrier.
• By carefully identifying individual carbon atoms in these molecules, scientists have learned that things get a little packed and that the two carbon atoms from the original oxaloacetate are the ones that are actually liberated as carbon dioxide.
• In order to produce the oxaloacetate, the initial acetate atoms are then relocated around toward the end of the cycle.