a Related Biological Terms

Describes the conditions and factors in the immediate environment. For example, the ambient temperature is the local temperature. The term is also used to describe room temperature (20°ree;C, 70°ree;F).

A widely used test to detect possible chemical carcinogens; based on mutagenicity in the bacterium Salmonella.

A nitrogen atom single-bonded to two hydrogen atoms.

Transfer RNA ( tRNA) molecule with its cognate amino acid attached.

enzyme that attaches an amino acid to its cognate tRNA(s).

Aminoglycoside is a medicinal and bacteriologic category of traditional Gram-negative antibacterial medications that inhibit protein synthesis and contain as a portion of the molecule an amino-modified glycoside (sugar). Aminoglycosides are also potent bactericidal antibiotics that act by creating fissures in the outer membrane of the bacterial cell. Research on aminoglycosides is still ongoing, and the main interests are (1) the mechanisms of action on the bacterial ribosome; (2) biosynthesis and physiology of aminoglycosides in their producers; (3) biochemistry and genetics of resistance determinants in both producers and clinically relevant bacteria, and (4) the recent molecular biological analysis of the biosynthetic potential of aminoglycosides producers.

Increases in concentration of this enzyme sometimes result in the elevation of toxic ammonia levels.

The common name for NH3, a strongly basic, irritating, colourlessgas which is lighter than air and readily soluble in water. It is formed in nature as a by-product of protein metabolism in animals by deamination of amino acids. Industrially, it is used in explosives, fertiliser, refrigerants, household cleaningsolutions, etc.

A prenatal diagnostic procedure in which X-ray of the mother's uterus, after injection of a radiopaque substance, allows visualization of the fetus, the placenta, and the uterine lining. This may be used to confirm a diagnosis of neural tube defects.

the innermost membranous sac enclosing the embryo of an amniote; it becomes filled with Amniotic fluid. One of the four amniote extraembryonic membranes; derived from the somatopleure (combination of ectoderm and somatic mesoderm). Used mainly for suspension and protection o fthe embryo.