A colourless liquid with a sharp unpleasant odour; produced by the bacterial breakdown of fatty acids and therefore found in sweat and some cheese.

A syrupy liquid formed by the dehydration of phosphoric acid; its salts, the pyrophosphates, are used in medicine.

(organic chemistry, biochemistry) A yellowish organic keto acid, 2-oxopropanoic acid, which occurs as an intermediate in many metabolic processes, especially glycolysis.

(organic chemistry) an equal mixture of the d- and l- forms of tartaric acid found in grape juice; the isomers can be separated via crystallization

(biochemistry) A derivative of vitamin A, used in the treatment of acne; it is essential for bone and tissue development.

(organic chemistry) an aliphatic dicarboxylic acid, (CH₂)₆(COOH)₂, obtained from cork; used in the manufacture of plastics

(organic chemistry) A crystalline unsaturated hydroxy fatty acid C₁₈H₃₄O₃ that yields esters important as plasticizers and whose glyceride (ricinolein) is the main component of castor oil.

(chemistry) a strong inorganic acid, HSO₂OH / (chemistry) the univalent functional group -SO₂OH

(biochemistry) A derivative of DNA having ribose in place of deoxyribose, and uracil in place of thymine; its primary function is in the transcription of genetic material and subsequent synthesis of protein.

(chemistry) an unsaturated aliphatic carboxylic acid, CH₃.CH:CH.CH:CH.COOH, found in Rowan berries, and used as a preservative