Protein
An organic molecule that consists of amino acids joined together in a specific sequence. Proteins are made inside cells by gene expression. They can have a variety of functions inside and outside cells, including giving cells their shape and structure. Some proteins are enzymes and speed up chemical reactions. Some are responsible for the movement of muscles. Others are hormones. Others are found in cell membranes and help transport atoms and molecules in and out of cells. They are a main constituent of many foods and an important part of a balanced diet (the amino acids released by the break down of proteins we have eaten are used by the body's cells to make new proteins).
