(organic chemistry) A liquid fatty acid, CH₃(CH₂)₄COOH, obtained from animal fats, and used in the manufacture of pharmaceuticals and flavours.

(organic chemistry) A white crystalline organic compound, N-cyclohexylsulfamic acid, whose salts, the cyclamates, have been used as artificial sweeteners

(biochemistry) A nonessential amino acid, L-α-amino-succinic acid, aminobutanedioic acid, found in animal protein and in sugar beet etc.

(organic chemistry) A long chain unsaturated fatty acid, CH₃(CH₂)₇CH=CH(CH₂)₁₁COOH, found in rapeseed and mustard seed oils; the cis- isomer is erucic acid, the trans- isomer is brassidic acid

(organic chemistry) An aromatic heterocyclic organic compound, C₃N₃(OH)₃, that decomposes on heating to form cyanic acid; it is a prebiotic compound found in stellar dust clouds.

(inorganic chemistry) the acid formally derived from sulphuric acid by replacing a hydroxyl (-OH) group by an amino (-NH₂) group - SO₂(OH)(NH₂)

(inorganic chemistry) An unstable acid, H₂S₂O₃, formally derived from sulfuric acid by the substitution of a sulfur atom in the place of an oxygen one; it is known only in solution or as its salts and esters, the thiosulfates.

(inorganic chemistry) An unstable acid, H₂S₂O₂, only known in solution, used as a reducing agent; its salts are hyposulfites).

(biochemistry) A water-soluble antioxidant vitamin, 3-[(2R)-2,4-dihydroxy-3,3-dimethylbutanamido]propanoic acid needed for the metabolism of carbohydrates, fats and proteins; it is found in cereals, legumes, meat and other foods

(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.