Question

The activity of the calcium pump on the sarcoplasmic reticulum of cardiac muscle is regulated by

a. Inositol triphosphate
b. Myosin light chain kinase
c. Phospholamban
d. Protein kinase A
e. Phospholipase C

Answer 1

The activity of the calcium pump on the sarcoplasmic reticulum of cardiac muscle is regulated by phospholamban, which is phosphorylated by protein kinase A.

Step-by-step explanation:

The activity of the calcium pump on the sarcoplasmic reticulum of cardiac muscle is regulated by phospholamban. Phospholamban is a regulatory protein that inhibits the activity of the calcium pump, preventing the active transport of calcium ions into the sarcoplasmic reticulum. When phospholamban is phosphorylated by protein kinase A, it relieves its inhibition on the calcium pump, allowing for the active transport of calcium ions into the sarcoplasmic reticulum.