Alkanes, alkenes, alcohols and carboxylic acids are different homologous series of organic compounds. Naturally occurring and synthetic polymers can be formed from a variety of monomers.
amino acidThe building blocks that make up a protein molecule. are moleculeA collection of two or more atoms held together by chemical bonds. which have at least two functional groups. All amino acids contain the -NH2 group and also the carboxylic acid group -COOH. Amino acids are polymerised in cells to make polypeptideA short polymer made from fewer than 50 amino acids. If the polymer contains more than 50 amino acids, it is called a protein. and proteinOrganic compound made up of amino acid molecules. One of the three main food groups, proteins are needed by the body for cell growth and repair..
Amino acids react by condensation polymerisationChemical reaction in which monomers (small molecules) join together to produce a polymer and a small molecule such as water. so for every monomer which is added to the growing polymer chain, one molecule of water is also produced.
For example, glycine is the simplest amino acid. An equation for the formation of a polypeptide which is made only from glycine is: