Question

in skeletal muscle cells, calcium initiates contraction by binding to
multiple choice
tropomyosin.
actin.
troponin.
myosin.
the thick filament.

Explanation:

In skeletal muscle cells, calcium binds to troponin. This binding causes a conformational change in the troponin - tropomyosin complex, which exposes the binding sites on actin for myosin, initiating muscle contraction.

Answer:

C. troponin