(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

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

A weak unstable acid, H₂CO₃, known only in solution, and as carbonate salts; it is present in carbonated drinks, and sparkling wine, but decomposes to form carbon dioxide and water.

(organic chemistry) an unsaturated organic dicarboxylic acid, HOOCCH=CHCOOH, the geometric isomer of maleic acid from which it may be prepared by heating; it is found in many plants, including fungi and mosses, and is essential in the chemistry of respiration; it has a number of industrial applications, and its esters, the fumarates, are used in the treatment of psoriasis

(organic chemistry) An unsaturated organic acid, trans-CH₃-CH=CH-COOH, found in croton oil and having many industrial uses; the cis- form is isocrotonic acid.

(biochemistry, organic chemistry) An organic compound, one of the gibberellins, obtained from the fungus Gibberella fujikuroi, that functions as a growth hormone in plants.

(inorganic chemistry) A transparent, colourless to pale yellow, fuming corrosive liquid, HNO₃; a highly reactive oxidizing agent used in the production of fertilizers, explosives, and rocket fuels and in a wide variety of industrial processes; once called aqua fortis.

(organic chemistry) A colourless crystalline compound, 2-hydroxy-1,2,3-propanetricarboxylic acid, C₆H₈O₇, found in citrus fruit; it is used as a food additive and in the manufacture of citrates.

(chemistry) a dicarboxylic acid, HOOC(CH₂)₃COOH, formed during the catabolism of tryptophan