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Wize University Biochemistry Textbook > Carbohydrate Metabolism

Malate-Aspartate Shuttle

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Malate Aspartate Shuttle


The main functions is to transfer NADH from the cytosol (made in glycolysis) to the matrix of the mitochondria so it can be used in the ETC
  • NADH can diffuse int the intermembrane space, but it needs a special system to get it past the second membrane

Simplified steps in the cycle

  1. Malate dehydrogenase converts malate to OAA and reduces NAD to NADH
  2. Transaminase converts OAA to aspartate. This reaction is coupled with glutamate --> alpha-ketogluterate
  3. products pumped across by aspartate pump
  4. coupled reactions turning aspartate into OAA and alpha-ketogluterate into glutamate
  5. OAA into malate and NADH --> NAD

Basically, rather than passing NADH through the membrane, we move the H+ through and remake the NADH on the other side.