Question

Select the CORRECT sequence of formation of given intermediates of Krebs' cycle.

• A. Succinate $\to$ Malate $\to$ Fumarate $\to$ OAA
• B. Fumarate $\to$ Succinate $\to$ Malate $\to$ OAA
• C. Succinate $\to$ Fumarate $\to$ Malate $\to$ OAA
• D. Malate $\to$ Fumarate $\to$ Succinate $\to$ OAA

Answer 1

Answer: (C)

Kreb's cycle which is also known as citric acid cycle is an amphibolic pathway occurring in all the living cells. It is a part of cellular respiratory process which is an energy yielding process. Its enzymatic reactions take place in the mitochondrial matrix. It is a process of redox reactions which begins with the formation of citrate from oxaloacetate and acetyl CoA. Citrate undergoes redox reactions to form several intermediates ultimately to form oxaloacetate which is one of the initial reactants of the cycle. Formation of succinate and fumarate is accompanied by formation of reduced NADH and $FAD{H}_2$ , which are then channelized through electron transport chain to form ATP.