The Link Reaction Connects Glycolysis to the Krebs Cycle
- Glycolysis (in the cytoplasm) breaks down glucose into pyruvate (3C).
- The Krebs cycle (in the mitochondrial matrix) processes acetyl groups (2C).
- There's a mismatch: pyruvate has 3 carbons, but the Krebs cycle needs 2-carbon acetyl groups.
- The link reaction bridges this gap by converting pyruvate (3C) into a 2-carbon acetyl group by removing one carbon and some hydrogens.
- The acetyl group is then attached to coenzyme A, forming acetyl-CoA.
- Think of the link reaction as a bridge connecting two cities: glycolysis in the cytoplasm and the Krebs cycle in the mitochondrial matrix.
- Without this bridge, energy flow would be interrupted.
Acetyl-CoA eventually carries the acetyl group into the Krebs cycle (more in C1.2.14)
Step-by-Step: How the Link Reaction Works
- Step 1: Decarboxylation (Removing Carbon)
- One carbon atom is removed from pyruvate (3C) as carbon dioxide (CO₂).
- This reduces pyruvate from 3 carbons to 2 carbons.
- Step 2: Oxidation (Removing Hydrogen)
