Question

Binding of acetylcholine to outer surface of endothelial cells, signals _____________________

(a) increase in cytosolic Ca^2+ concentration

(b) decrease cytosolic Ca^2+ concentration

(c) increase in acidity

(d) increase in basicity

The question was posed to me in an international level competition.

My query is from Cell Signaling and Signal Transduction topic in section Cell Signaling and Signal Transduction of Cell Biology

Answer 1

Right choice is (a) increase in cytosolic Ca^2+ concentration

To explain: Binding of acetylcholine to the outer surface of endothelial cells signals an elevation of cytoplasmic concentration of calcium ions, that activates the enzyme nitric oxide synthase.