Abbe refractometer a refractometer in which the critical angle for total reflection at the interface of a film of liquid between two similar glass prisms is used in determining the refractive index of the liquid. [After Ernst Abbe (1840–1905), German physicist famous for his researches in optics.]

Aarskog–Scott syndrome or Aarskog syndrome or faciogenital dysplasia an extremely rare genetically heterogeneous developmental disorder in which individuals have widely spaced eyes, anteverted nostrils, a broad upper lip and a ‘saddlebag’ or ‘shawl scrotum’. The X-linked form has been ascribed to mutations in the FGD1 gene. [After Dagfinn Aarskog (1928– ), Norwegian paediatrician, and Charles

abbreviation for ATPase associated with varied activities; any member of a family of conserved ATP-dependent proteases that mediate degradation of nonintegrated membrane proteins in bacteria, mitochondria, and chloroplasts. They form large complexes composed of identical or homologous subunits. Each subunit contains two transmembrane segments, an ATP-binding omain, and a metal-dependent catalytic domain. Mitochondria contain a matrix-facing