aminotransferase

aminotransferase An enzyme that catalyzes the transfer of an amino group from a donor molecule to a recipient molecule. The donor molecule is usually an amino acid and the recipient molecule is usually an alpha-2 keto acid. Two of the best-known enzymes in this class are serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic…

amino acid

amino acid One of the 20 building blocks from which proteins are assembled. Isoleucine, leucine, lysine, phenylalanine, threonine, tryptophan, and valine are deemed “essential” amino acids because the human body cannot make them and they must be obtained in the diet. Amino acids are sometimes taken orally in supplement form.

amenorrhea, secondary

amenorrhea, secondary The cessation of menstruation for abnormal reasons. Causes include anorexia nervosa, disease of the female reproductive tract, and overexercise. Secondary amenorrhea can also be caused by certain medications, notably the birth control medication medroxyprogesterone (brand name: Depo-Provera); in this case, amenorrhea is an expected effect.