18.2 The Link Reaction

Question 1

Where does the link reaction take place? (1 mark)

Answer 1

The mitochondrial matrix

Question 2

Why is the outer mitochondrial membrane important? (1 mark)

Answer 2

It separates the contents of the mitochondria from the rest of the cell , maintaining ideal conditions for aerobic respiration.

Question 3

How do the cristae, in the mitochondria, aid respiration? (1 mark)

Answer 3

They provide a large surface area for phosphorylation.

Question 4

What two important things for respiration does the inner mitochondrial membrane contain? (2 marks)

Answer 4

Electron transport chains
ATP synthase

Question 5

What is another name for the link reaction? (1 mark)

Answer 5

Oxidative decarboxylation

Question 6

What does the link reaction do? (1 mark)

Answer 6

Links the anaerobic glycolysis (in the cytoplasm) to the aerobic steps (in the mitochondria).

Question 7

Where does the pyruvate used in the link reaction come from? (1 mark)

Answer 7

Glycolysis

Question 8

How many carbons are in pyruvate? (1 mark)

Answer 8

Three

Question 9

Describe the link reaction. (4 marks)

Answer 9

1. Pyruvate enters the mitochondrial matrix.
2. The pyruvate undergoes decarboxylation and dehydrogenation, this forms an acetyl group.
3. This acetyl group binds with coenzyme A, to produce acetlycoenzymeA.

Question 10

What is the hydrogen removed from the pyruvate then used for? (1 mark)

Answer 10

Used to reduce NAD.