Gluconeogenesis

Question 1

To avoid hypoglycaemia

Answer 1

• breakdown liver glycogen stores occurs to maintain plasma glucose levels.
• release free fatty acids from adipose tissue.
• convert Acetyl CoA into ketone bodies via the liver.

Question 2

Gluconeogenesis

Answer 2

Conversion of pyruvate into glucose via multiple steps
Involves non carbohydrate precursors (lactate, amino acids, glycerol) and the bypass of key steps by non-glycolytic enzymes

Question 3

Irreversible reactions - glycolysis

Answer 3

3, catalysed by kinases: hexokinase, phosphofructokinase and pyruvate kinase

Question 4

Bypassing requires

Answer 4

4 additional enzymes - first reaction in mitochondria, remainder are cytosolic

Question 5

Bypass function

Answer 5

4 additional high energy bonds are required to turn the process into an energetically feasible one
Δ G for reversal of glycolysis = +90, hence not possible