alleles

Alternative forms of a gene at a particular site on a chromosome.

aldose

A monosaccharide whose C-1 carbon atom contains an aldehyde group.

aldol condensation

The combination of two carbonyl compounds (e.g., an aldehyde and a ketone) to form a β-hydroxycarbonyl compound, or aldol.

alcoholic fermentation

The anaerobic conversion of glucose into ethanol with the concomitant production of ATP.

alcaptonuria

A relatively harmless hereditary disorder resulting from the aberrant breakdown of tyrosine and phenylalanine.

agonists

Molecules that bind to receptor proteins and trigger signaling pathways.

affinity labeling

A means of mapping the active site of an enzyme by using a substrate analog that binds to the active site and forms a covalent bond with a nearby amino acid.