First 137 words of the document:
Definition: The building blocks of proteins.
There are 20 different amino acids. Amino acids are
linked together to form small chains of amino acids.
These chains link together to form proteins.
Of the 20 amino acids, 11 can be synthesized in the
body. That leaves nine amino acids that you need to
get directly from your diet. Those nine amino acids
are called "essential amino acids."
A molecule composed of polymers of amino acids
joined together by peptide bonds. It can be
distinguished from fats and carbohydrates by
containing nitrogen. Other components include
carbon, hydrogen, oxygen, sulphur, and sometimes
Polypeptide: A peptide consisting of 2 or more
amino acids. Amino acids make up polypeptides
which, in turn, make up proteins.