Significance of citric acid cycle:
(i) It explains the process of breaking of pyruvate into CO2 and water. It is major pathway of generation of ATP.
(ii) More energy is released (24 ATP) in this process, as compared to glycolysis.
(iii) In Kreb's cycle, carbon skeletons are obtained for use in growth and maintenance of the cell. Many intermediate compounds are formed. They are used in the synthesis of other biomolecules like amino acids, nucleotides, chlorophyll, cytochromes and fats. Succinyl CoA is the starting molecule for synthesis of chlorophyll. Amino acids are synthesized from aketoglutaric acid, pyruvic acid, and oxaloacetic acid.
Pyruvic acid + 4 NAD+ + FAD + 2H2O + ADP + Pi \(\underset{Matrix}{\stackrel{Mitochondrial}{\rightarrow}}
\) 3CO2 + 4NADH + 4H+ + FADH2 + ATP
