A
biomolecule is a
molecule that naturally occurs in living organisms. Biomolecules consist primarily of
carbon and
hydrogen, along with
nitrogen,
oxygen,
phosphorus and
sulfur. Other elements sometimes are incorporated but are much less common.
All known forms of life are composed solely of biomolecules. For example, humans possess skin and hair. The main component of hair is keratin, an agglomeration of proteins which are themselves polymers built from amino acids. Amino acids are some of the most important building blocks used in nature to construct larger molecules. Another type of building block are the nucleotides, each of which consists of three components either a purine or pyrimidine base, a pentose sugar and a phosphate group. These nucleotides mainly form the nucleic acids.
Besides the polymeric biomolecules, numerous organic molecules are absorbed by living systems.
A diverse range of biomolecules exist, including
