Question

Describe the connecting link between glycolysis and Krebs’ cycle.

Answer 1

a. Each pyruvic acid molecule formed in glycolysis undergoes oxidative decarboxylation (i.e. oxidation by dehydrogenation and decarboxylation by loss of CO2), to form Acetyl group (2C), which combines with Co-A to form Acetyl Co-A.
b. Thus, pyruvic acid is converted to Acetyl Co-A. This is called Acetylation of Pyruvate.
c. It involves several reactions, many enzymes and co-factors.
d. Hydrogen released combines with NAD to form reduced co-enzyme NADH2, which has the potential to form 3ATP in ETS.
e. In this process, CO2 is released.
f. Acetyl Co-A is a connecting link between glycolysis and Krebs cycle.
g. Summary is represented as:
2PA+2 Co-A+2NAD`"Enzyme Complex (pyruvic dehydrogenase)"/""`2Acetyl Co-A+2CO₂↑+2NADH₂