Answer in detail. Explain the Krebs cycle with reaction.

Question 15.

Answer in detail.

Explain the Krebs cycle with reaction.


Answer:

The Krebs cycle is also called tricarboxylic acid (TCA) cycle or the citric acid cycle. It takes place in the matrix of the mitochondria.

The cycle starts with the reaction between acetyl-CoA and the four-carbon oxaloacetate to form six-carbon citric acid. Through the next steps of the cycle, two of the six carbons of the citric acid removed as carbon dioxide (CO2) to yield the four-carbon compound, oxaloacetate, which is used again in the first step of the next cycle. During the eight reactions that take place, for every molecule of acetyl-CoA the cycle produces three NADH and one flavin adenine dinucleotide (FAD/FADH2), along with one molecule of ATP.


The net equation of the Krebs cycle:


Acetyl CoA + 3 NAD + FAD + ADP + HPO4-2 ——> 2 CO2 + CoA + 3NADH+ + FADH+ + ATP