∞ generated and posted on 2016.01.14 ∞
Associations of covalently bonded atoms that supply additional chemistries to hydrocarbons, particularly by replacing hydrogen atoms.
Functional groups often are hydrophilic, thus supplying to hydrocarbons both full and partial charges, converting these otherwise hydrophobic compounds to some degree into polar substances. Indeed, a common component of functional groups found in biomolecules is the highly electronegative oxygen but so too is nitrogen found in amino groups and their derivatives as well as the oxygen-similar sulfur (sulfhydryl groups).
Hydrophobic functional groups also exist, particularly as the radical groups of amino acids. It is no exaggeration to note that much of functioning of biological systems can be directly traced to various functional groups.
At a minimum, it is helpful in looking at biomolecules to be aware of what is and what is not hydrophilic (and where on the molecule the polar groups are located). At a higher level of biological appreciation, one can distinguish the functioning of different groups towards understanding the chemistry of individual molecules, such as the acidity of carboxyl groups. At still higher levels one can follow specific interactions between molecules, via functional groups, to gain an understanding, for example, of both enzymatic functioning and protein folding.