Question

Which protein is a key component of the contractile elements in vascular smooth muscle responsible for regulating muscle contraction?

a) Troponin

b) Tropomyosin

c) Myosin

d) Actin

Answer 1

Tropomyosin is the key protein responsible for regulating muscle contraction in vascular smooth muscle.

Step-by-step explanation:

The key protein responsible for regulating muscle contraction in vascular smooth muscle is tropomyosin. In relaxed muscle, tropomyosin covers the myosin-binding sites on actin filaments, preventing muscle contraction. When calcium ions bind to troponin, it causes a conformational change in tropomyosin, exposing the myosin-binding sites and allowing for muscle contraction.