Transition reaction

Definition

The transition reaction is a crucial metabolic process where pyruvate is converted into acetyl-CoA, linking glycolysis to the Krebs cycle. This reaction takes place in the mitochondrial matrix and involves decarboxylation and reduction of NAD+.

5 Must Know Facts For Your Next Test

1. Pyruvate dehydrogenase complex (PDC) catalyzes the transition reaction.
2. In this process, one molecule of CO2 is released for each pyruvate molecule converted.
3. NAD+ is reduced to NADH during the conversion of pyruvate to acetyl-CoA.
4. The transition reaction does not directly produce ATP but generates NADH, which enters the electron transport chain.
5. This reaction occurs in the absence of oxygen (anaerobic conditions), leading to fermentation instead of entering the Krebs cycle.

Review Questions

Related terms

Glycolysis:

A series of reactions that break down glucose into pyruvate, producing ATP and NADH.

Krebs Cycle:

A series of enzymatic reactions that produce energy through oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins.

Electron Transport Chain:

A sequence of proteins within mitochondria that transfer electrons from NADH and FADH2 to oxygen, generating ATP.