Proteins are macromolecules that play a critical role in virtually all biological processes. They are involved in structural support, transport, signaling, catalysis, and defense against disease, among other functions. Proteins are made up of amino acids, which are linked together by peptide bonds to form polypeptide chains. These chains then fold into three-dimensional structures that are crucial for their function. Proper protein intake is essential for maintaining muscle mass, regulating hormone levels, and supporting immune function, among other benefits.