A protein is a naturally occurring, extremely complex substance that consists of amino acid residues joined by peptide bonds. Proteins are present in all living organisms and include many essential biological compounds such as enzymes, hormones, and antibodies.
Amino acids are organic compounds that combine to form proteins. Amino acids and proteins are the building blocks of life.
When proteins are digested or broken down, amino acids are left. The human body uses amino acids to make proteins to help the body.
Protein has many roles in your body. It helps repair and build your body's tissues, allows metabolic reactions to take place and coordinates bodily functions. In addition to providing your body with a structural framework, proteins also maintain proper pH and fluid balance.
Once a protein source reaches your stomach, hydrochloric acid and enzymes called proteases break it down into smaller chains of amino acids. Amino acids are joined together by peptides, which are broken by proteases. From your stomach, these smaller chains of amino acids move into your small intestine.
Too little protein may cause changes in body composition that develop over a long period of time, such as muscle wasting. The most severe form of protein deficiency is known as kwashiorkor. It most often occurs in children in developing countries where famine and imbalanced diets are common.