Understanding:
• In aerobic cell respiration pyruvate is decarboxylated and oxidised, and converted into acetyl compound and
attached to coenzyme A to form acetyl coenzyme A in the link reaction
The first stage of aerobic respiration is the link reaction, which transports pyruvate into the mitochondria
- Aerobic respiration uses available oxygen to further oxidise the sugar molecule for a greater yield of ATP
The link reaction is named thus because it links the products of glycolysis with the aerobic processes of the mitochondria
- Pyruvate is transported from the cytosol into the mitochondrial matrix by carrier proteins on the mitochondrial membrane
- The pyruvate loses a carbon atom (decarboxylation), which forms a carbon dioxide molecule
- The 2C compound then forms an acetyl group when it loses hydrogen atoms via oxidation (NAD+ is reduced to NADH + H+)
- The acetyl compound then combines with coenzyme A to form acetyl coenzyme A (acetyl CoA)
As glycolysis splits glucose into two pyruvate molecules, the link reaction occurs twice per molecule of glucose
- Per glucose molecule, the link reaction produces acetyl CoA (×2), NADH + H+ (×2) and CO2 (×2)
The Link Reaction
