During contraction, what must happen to the troponin for muscle contraction to proceed?

For muscle contraction to proceed, troponin needs to bind to calcium ions. This binding is crucial because troponin is a regulatory protein that plays a key role in the contraction process within muscle fibers. In a resting muscle, tropomyosin, another regulatory protein, prevents the interaction between actin and myosin by covering the binding sites on the actin filaments. When calcium ions are released from the sarcoplasmic reticulum in response to a nerve impulse, they bind to troponin. This binding causes a conformational change in the troponin-tropomyosin complex, shifting tropomyosin away from the actin binding sites. Subsequently, myosin heads can attach to actin, leading to cross-bridge formation, which is essential for muscle contraction to occur.