Trans
From Wikipedia, the free encyclopedia
Trans is a Latin noun or prefix, meaning "across", "beyond" or "on the opposite side [of]" . It is the opposite of cis, which means "on the same side [of]".
- In chemistry, a double bond (or ring not subject to free rotation in which the greater radical on both ends is on the opposite side of the bond (or face of the ring) is called trans. Compare with cis.
- In the diagram on the right, the hydrogen atoms are on opposite sides of the carbon chain. They cannot rotate to the same side of the molecule, as (unlike with a single bond) double bonds prevent this from happening. A similar phenomenon is seen in cyclic compounds (in which the atoms form a closed ring), where substituents can be on the same "face" of the ring (cis) or opposite faces (trans.)
- See geometric isomerism for more on this topic. See also Trans fat.
- In cell biology, external factors which act on a molecule are considered to act in trans. For example, proteins which are transcription factors bind to the DNA in trans to modify the rate of RNA transcription. Internal factors act in cis. For example, a specific promoter sequence which recruits RNA polymerase and thereby increases the rate of RNA transcription acts in cis.
- In geography, placenames beginning with the prefix Trans- convey the meaning "beyond" or "across" something. Examples include Transalpine Gaul (from Rome's viewpoint, Gaul on the opposite side of the Alps), Transkei (referring to the Kei River), Transvaal (Vaal River), Transleithania (Leitha), Transmuraland (Mura), Transoxiana (Oxus), Transsiberian (Siberia), Transjordan (a historical country in the Middle East), Transcaucasus (Caucasus mountains). The antonym is Cis-.
- In astronomy translunar means: in outer space outside the Moon's orbit. Cislunar is its antonym. Similarly, a Trans-Neptunian object is a celestial object orbiting the Sun outside the orbit of Neptune, and Cis-Neptunian objects are at or before Neptune's orbit.
- In medicine and sociology, transgender and transsexual (e.g. a transwoman, transman) are the opposite of cisgender and cissexual, respectively. Both describe people whose gender identity matches their physical and/or assigned sex. The term also serves as an umbrella term to include the entire trans community, although some (such as genderqueer and other gender variant people) do not use labels with the prefix.
Trans is also:
- Trans, Switzerland, a municipality in the Grisons
- Trans, a commune in the Mayenne département, in France;
- Trans-en-Provence, a commune in the Var département, in France;
- a shortname for Trans World Airlines (TWA) airline company
- Trans (album) 1982 album by Neil Young.
