Question

High levels of glucagon in the blood can:

a) Inhibit glycolysis by the liver

b) Inhibit glycogen breakdown by the liver

c) Stimulate glycogen synthesis by the liver

d) Stimulate glucose uptake by the liver

Answer 1

Glucagon :-
• This hormone is secreted by alpha cells of pancreas.
• This is a diabetogenic hormone because it increases blood glucose level.

Action :-
• Block glycolysis -
This hormone acts on liver and blocks glucose breakdown or glycolysis. This results into increased blood glucose.
• Glucose release -
This hormone acts on liver and increases release of glucose.
• Gluconeogenesis -
Glucagon stimulates glucose formation from non carbohydrate sources like protein, this process is called gluconeogenesis.
• Glycogen break down/ glycogenolysis -
This is process of breakdown of glycogen to glucose 1 phosphate. This is stimulated by glucagon.

Insulin :-
• This hormone acts against glucagon and maintains blood glucose level.
It decreases blood glucose levels by inhibiting glycogen breakdown, stimulating glycogen synthesis by liver and stimulating glucose uptake by liver.

Now in question,
Option (A) is correct answer.
Increased glucagon will inhibit glycolysis in liver.

Other options -
• These are functions of insulin not glucagon.