Question

Alternate name of Krebs’ cycle is
A) TCA cycle
B) Citric acid cycle
C) Both A and B
None of these

Answer 1

Krebs’ cycle is the process of oxidation of glucose, fatty acid and amino acids to produce energy. It occurs in all aerobic organisms. It takes place in the matrix of mitochondria.

Complete answer:
Krebs’ cycle is an important metabolic pathway that connects carbohydrate, fat and protein metabolism. It is a series of chemical reactions in which the energy in the form of ATP is produced by the oxidation of acetyl –CoA which is obtained from Carbohydrate, fats and protein.
It is an eight step process in which redox, dehydration, hydration, and decarboxylation reactions take place. It uses a two and four carbon molecule to produce a six carbon molecule which further produces carbon dioxide, ATP and NADH and FADH2.
The name of this pathway is also called as citric acid or tri-carboxylic acid pathway as citrate is consumed and regenerated in the series of reactions to complete the cycle. The NADH generated by this cycle enters oxidative phosphorylation.

The correct answer is (C). Alternate name of Kreb’ cycle is TCA and citric acid cycle.

Note: In the prokaryotic cell, the TCA cycle takes place in the cytosol due to the absence of mitochondria. At the end the 4 carbon oxaloacetates are produced. NADH and FADH2 produced in the TCA cycle are used up in the oxidative phosphorylation to produce 2.5 and 1.5 ATP respectively.