Amino acids are organic compounds that serve as the building blocks of proteins. In human metabolism, about twenty different amino acids play a role. They link in varying sequences to form chains, which makes the diversity of proteins in the body possible. Every amino acid has a common basic structure but differs in a variable side chain that determines its chemical properties.
In practice, a distinction is made between essential and non-essential amino acids. The body cannot make essential amino acids itself in sufficient amounts and has to take them in through food, more on this in the entry Essential amino acids. Under normal conditions the body can produce non-essential amino acids itself. For a balanced supply, the raw amount of protein therefore matters less than a varied selection of protein sources.
Individual amino acids such as leucine are a particular focus when it comes to muscle metabolism. For a general overview of the nutrient protein, see the entry Protein.
