Krebs Cycle and the Electron Transport Chain

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. 
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