Biochemists study the chemistry of life. Living things exhibit a large varitey of activities: eating; sleeping; moving; talking; thinking . The unique chemical reactions behind these activities are due to biomolecules which contain specific functional groups.

A functional group is a group of atoms within a molecule, which makes it react in a certain way - gives it its chemical character. Biological molecules often have more than one functional group.

The functional group in fats is the carboxylic acid group:

Fats or Lipids are often called fatty acids. Generally, fatty acids have a long hydrocarbon chain with a carboxylic acid group on the end. Saturated fats contain all single bonds in the hydrocarbon chain. Polyunsaturated fats contain some double bonds between carbon atoms in the hydrocarbon chain.

These fatty acids do not actually exist in that form in fats and oils; they are present in the form of esters, the result of a reaction between a carboxylic acid and an alcohol,glycerol. Glyderol is a compound which has three alcohol groups, and these combine with three fatty acid molecules to form a triglyceride. Triglycerides serve as energy storage compounds. Cholesterol is also a lipid found in the body.

Bibliography

Martin, D. & Sampugna, J. Molecules in Living Systems (New York: Harper & Row, 1973).