Proteins make up most of the body weight after water. Proteins are required for growth and development of all body tissues. They are the major source of building material for muscles, blood, skin, hair, nails, and internal organs, including the heart and brain. Protein is needed for the formation of hormones which control a variety of body functions such as growth, sexual development, and rate of metabolism. Protein also helps prevent the blood and tissues from becoming either too acid or too alkaline and helps regulate the body’s water balance.
Proteins are more complex than carbohydrates or fats. When a protein food is ingested, the body breaks it down into amino acids. Ribosomes in each cell receive coded messages from DNA in the cell nucleus on how to put these amino acids together in chains. There are 20 amino acids and they can be combined in numerous ways, like the letters in the alphabet. When a protein chain is finished, its chemical, electrical, and sequential (the sequence of amino acids) characteristics result in a unique coiled three-dimensional shape which is important because the shape alone enables the protein to perform a specific function.