Krebs Cycle and the Electron Transport Chain
1. Describe how the Krebs cycle produces carbon dioxide, ATP, reduced NAD and reduced FAD
The Link Reaction
- If oxygen is available, pyruvate created from glycolysis travels to the mitochondria where it is oxidised to form carbon dioxide and water.
- Pyruvate is decarboxylated - carbon dioxide is released as a waste product.
- Pyruvate is dehydrogenated - two hydrogens are removed and taken up by the coenzyme NAD.
- A 2C molecule results and combines with coenzyme A to form acetyl coenzyme A (Acetyl CoA).
- The 2C acetyl groups are carried to the Krebs cycle by coenzyme A.
The Krebs Cycle
- Occurs in the matrix of the mitochondria (so does the link reaction)
- Purpose is to supply a continuous flow of hydrogen (and electrons) to the electron transport chain.
- Each 2C acetyl coenzyme A combines with a 4C compound to create a 6C compound.
- A circule of reactions recreate the original 4C compound.