Which one of the following statements concerning skeletal mu

Which one of the following statements concerning skeletal muscle metabolism is correct?

            a.         Muscle glycogen breakdown during exercise produces glucose for release into the blood.

            b.         Glycogen breakdown during contraction is stimulated by Ca²⁺, which activates phosphorylase kinase, that in turn phosphorylates and activates glycogen      phosphorylase.

            c.         Conditions that promote protein kinase activities increase glycogen synthesis, while conditions that promote protein phosphatase activity increase glycogen breakdown.

            d.         Glycogen synthase activity cannot be controlled at the same time as glycogen. phosphorylase activity or the muscle could not generate glucose for energy production.

            e.         Glucose uptake from the blood, via the translocation of GLUT4 transporters to the sarcolemma, is stimulated by epinephrine.

Solution

b. Glycogen breakdown during contraction is stimulated by Ca2+, which activates phosphorylase kinase, that in turn phospharylates and activates glycogen phosphorylase. This statement is correct among all.