What primary biological role do proteins have?

Proteins play a crucial role in the body primarily by building and repairing tissues. They are composed of long chains of amino acids that fold into complex three-dimensional structures, allowing them to perform a vast array of functions essential for life. One of the key functions of proteins is to serve as structural components of cells and tissues. For instance, collagen provides strength to connective tissues, while keratin is a critical component of hair and skin.

In addition to structural roles, proteins are involved in numerous biological processes such as catalyzing biochemical reactions as enzymes, facilitating communication within and between cells as hormones, and responding to environmental changes as part of the immune response. The versatility of proteins makes them fundamental to growth, development, and maintenance of all living organisms.