Link Reaction

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•  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

link reaction