To begin the actual contraction, calcium ions must first bind to ____ in the muscle cell.

A) actin
B) myosin
C) troponin
D) sarcoplasmic reticulum
E) T tubules

Calcium Ions

Charged calcium particles (Ca2+) that play critical roles in biological processes, including muscle contraction, neurotransmitter release, and cell signaling.

Troponin

A regulatory protein in the actin filaments of muscle fibers.

Actin

Actin is a globular protein that forms filaments, which are crucial for various cellular processes including muscle contraction and cell motility.