Question

Which of the following is FALSE regarding skeletal muscle cells with a constitutively active mutant form of PKA that remains constantly on, in the context of adrenaline stimulation and glycogen breakdown?

a) Glycogen phosphorylase is activated continuously
b) Adrenaline stimulation has no effect on glycogen breakdown
c) Constitutively active PKA leads to persistent glycogen breakdown
d) The normal regulatory control of PKA is overridden

Answer 1

The correct answer is (b) Adrenaline stimulation has no effect on glycogen breakdown.

Step-by-step explanation:

The correct answer to the question is b) Adrenaline stimulation has no effect on glycogen breakdown. In skeletal muscle cells with a constitutively active mutant form of PKA, glycogen phosphorylase is activated continuously, leading to persistent glycogen breakdown. Adrenaline stimulation normally activates PKA and leads to glycogen breakdown, but in cells with a constitutively active mutant form of PKA, the normal regulatory control of PKA is overridden, leading to continuous glycogen breakdown.