Question

Which of the following is NOT an intermediate of TCA Cycle?

• A. Acetyl CoA
• B. Citrate
• C. Succinyl CoA
• D. Alpha Ketoglutarate

Answer 1

The correct option is A Acetyl CoA

TCA cycle or Tricaboxylic Cycle is also known as Kreb’s Cycle or Citric Acid Cycle. It is the second stage of cellular respiration that occurs in the matrix of mitochondria. All the enzymes involved in the citric acid cycle are soluble.

It is an aerobic pathway because NADH and FADH₂ produced transfer their electrons to the next pathway which will use oxygen. If the transfer of electrons does not occur, no oxidation takes place. Very little ATP is produced during the process directly.

TCA cycle starts when acetyl coA binds to oxaloacetate forming citrate. The coenzyme A is relaesed during this step. So, both acetyl coA and oxaloacetate are not intermediates of TCA cycle.