Links Reaction

Question 1

What enzyme is used during the links reaction?

Answer 1

Pyruvate dehydrogenase

Question 2

What reactions are targeted in metabolism regulation and why?

Answer 2

Unidirectional (non reversible ones)

They can be rate limited because we can control the volume of substrates

Question 3

The reaction catalysed by pyruvate dehydrogenase is a large multienzyme complex that requires various cofactors (ie FAD). What vitamins provide these and therefore what type of deficiency is the links reaction sensitive to?

Answer 3

B vitamins

Vitamin B1 deficiency

Question 4

Why is the links reaction irreversible?

Answer 4

Because CO2 is released

Question 5

Name some substances that activate Pyruvate dehydrogenase, why do they activate it?

Answer 5

Pyruvate
NAD+
ADP
Insulin

Substrates and molecules signalling low energy activate it

Question 6

What substances would inhibit Pyruvate dehydrogenase and why?

Answer 6

Acetyl-CoA
NADH
ATP
Citrate

High energy molecules and products of the links reaction inhibit it

Question 7

What does a PDH deficiency result in and why?

Answer 7

Lactic acidosis

Because the Pyruvate is diverted through lactate dehydrogenase which results in the production of lactate