This ion is critical for normal excitation- contraction coupling, but is not necessary for contraction of the glycerinated muscle fibers you worked with in the lab.

Question

Quizplus · Accepted Answer

Calcium ions (Ca2+) are critical for normal excitation-contraction coupling in muscle cells, facilitating the interaction between actin and myosin necessary for muscle contraction. However, in glycerinated muscle fibers, where cellular membranes are disrupted, contraction can be induced by directly adding ATP in the absence of Ca2+.

This Ion Is Critical for Normal Excitation- Contraction Coupling, but Is