The Link Reaction

Question 1

Where does the Link Reaction Occur?

Answer 1

Mitochondrial matrix

Question 2

What happens at the start of the link reaction?

Answer 2

• Pyruvate from glycolysis contains a lot of chemical energy
• When enough O2 available, Pyruvate moves across double membrane of mitochondria via active transport from cytoplasm to matrix
• This requires a transport protein and a small amount of ATP

Question 3

What are the key steps of the link reaction?

Answer 3

• Pyruvate is dehydrogenated and decareboxylated by enzymes forming acetate and CO2 (NAD reduced o NADH)
• Catalysed by pyruvate dehydrogenase
• NAD recieves 2 H atoms
• Combined with coenzyme A forming acetyl coenzyme A

Question 4

What are the products of Link reaction?

Answer 4

• Acetyl coenzyme A
• CO2
• NADH

Question 5

What is the role of coenzyme A?

Answer 5

• Not used up
• Nucleoside and a vitamin
• Binds to acetate forming Acetyl CoA
• Then fed to Kreb’s cycle