Seen Question

Question 1

What is the purpose of the gluconeogenisis pathway?

Answer 1

Gluconeogenisis synthesises glucose molecules from non-carbohydrate precursors including pyruvate,

citric acid cycle intermediates,the carbon skeletons of most amino acids and glycerol

Pathway is important for the maintenance of blood glucose levels when glucose and glycogen stores in boys have been depleted (starvation or vigorous excercise)

Gluconeogenisis is glycolysis in reverse

Question 2

How dose the pathway connect to other pathways ??

Answer 2

Gluconeogenisis is directly connected to the pentose phosphate pathway, as the need for glucose-6-phosphate increases

So dose the activity of gluconeogenisis

The glucose molecules created during gluconeogenisis can be used by cells to fuel glycolysis

Question 3

What metabolic conditions or processes turn the pathway on and off?

Answer 3

Low blood glucose will turn pathway on, high blood glucose will turn pathway off.

Production of lactate, glycerol , alanine and glutamine will turn the pathway on lack of these will turn them off

Question 4

State a structural feature which is important for the function and interaction of one of the regulatory molecules in the pathway, explain why this feature is important ?

Answer 4

The conversion of phosphenol-pyruvate to pyruvate, is catalysed by pyruvate kinase is an irreversible step in the pathway.

Once this step has completed then the pathway is committed to producing glucose

It is limiting because it is very spontaneous reaction. energy is released to surroundings

bonds being forming stronger bonds than the bonds being broken

Question 5

Name a biochemical technique used to study this pathway ?

Answer 5

Radioactive and stable-labelled isotopes used to quantitate the contribution and regulation of gluconeogenisis

Question 6

Name on specific drug or disease associated with the pathway ans state how the drug or disease is associated with pathway ?

Answer 6

Glucose-6-phosphate deficiency is a defect in the release of glucose from glucose-6-phosphate affects gluconeogenisis

It presents with an abnormal enlargement of the liver, short stature and obesity