Question

anesthesiabuddy 2h
what ion directly binds troponin to initiate skeletal muscle contraction?
guess my favorite...
a sodium
b potassium
c calcium
d magnesium

Explanation:

In skeletal muscle contraction, when an action potential reaches the muscle fiber, calcium ions are released from the sarcoplasmic reticulum. These calcium ions directly bind to troponin, which causes a conformational change that moves tropomyosin away from the actin-binding sites, allowing cross-bridge formation and muscle contraction to begin. Sodium and potassium are involved in generating action potentials, while magnesium has a regulatory role but does not directly bind troponin to initiate contraction.

Answer:

C. calcium