Calcium binding refers to the process by which calcium ions (Ca²⁺) attach to specific sites on proteins or other molecules. This interaction is crucial for various biological functions, including muscle contraction, neurotransmitter release, and blood clotting. Proteins that bind calcium often undergo conformational changes, which can activate or inhibit their functions. Many proteins, such as calmodulin and troponin, are known for their ability to bind calcium. These proteins play essential roles in cellular signaling and muscle physiology. The binding of calcium can trigger a cascade of events that ultimately lead to physiological responses in the body.