In contracting skeletal muscle, a sudden elevation of cytosolic Ca2 concentration will result in: Inactivation of phosphorylase
kinase caused by the action of protein phosphatase. Activation of cAMP-dependent protein kinase. Dissociation of cAMP-dependent protein kinase into catalytic and regulatory subunits. Conversion of cAMP to AMP by phosphodiesterase. Activation of phosphorylase kinase.
ACTIVATION OF PHOSPHORYLASE KINASE AND ALLOSTERICALLY ACTIVATION OF PHOSPHORYLASE KINASE B
Explanation:
In a contracting skeletal muscle, there is a rapid need of ATP by the muscle cell. The energy need is obtained by the degradation of glycogen into glucose which then enters glycolysis. Muscle contraction causes muscle depolarization in which there is the rapid influx of calcium ions from the sarcoplasmic reticulum into the sacroplasm of the myocytes. This in turn causes the binding of calcium ion with calmodulin which thenb activates phosphorylase kinase from which it allosterically activate the b form of the enzyme needed for the conversion of glycogen to glucose. The other options do not occur as a result of increase in cytolic calcium concentration.
