| amino acids | Organic compounds that generally contain an amino (-nh2) and a carboxyl (-cooh) group. Twenty alpha-amino acids are the subunits which are polymerised to form proteins. (12 Dec 1998) |
|---|---|
| amino acids, branched-chain | Amino acids which have a branched carbon chain. (12 Dec 1998) |
| amino acids, cyclic | A class of amino acids characterised by a closed ring structure. (12 Dec 1998) |
| amino acids, peptides, and proteins | Amino acids and chains of amino acids connected by peptide linkages. (12 Dec 1998) |
| essential amino acids | Alpha-amino acids nutritionally required by an organism and which must be supplied in its diet (i.e., cannot be synthesised by the organism) either as free amino acid or in proteins. (05 Mar 2000) |
| excitatory amino acids | Endogenous amino acids released by neurons as excitatory neurotransmitters. Glutamic acid is the most common excitatory neurotransmitter in the brain. Aspartic acid has been regarded as an excitatory transmitter for many years, but the extent of its role as a transmitter is unclear. (12 Dec 1998) |
| biological standard unit | A specific quantity of biologically active reference material (antibiotic, antitoxin, enzyme, hormone, vitamin, etc.). (05 Mar 2000) |
| gold standard | Term used to describe a method or procedure that is widely recognised as the best available. Origin: jargon (05 Mar 2000) |
| standard | 1. A flag; colours; a banner; especially, a national or other ensign. "His armies, in the following day, On those fair plains their standards proud display." (Fairfax) 2. That which is established by authority as a rule for the measure of quantity, extent, value, or quality; especially, the original specimen weight or measure sanctioned by government, as the standard pound, gallon, or yard. 3. That which is established as a rule or model by authority, custom, or general consent; criterion; test. "The court, which used to be the standard of property and correctness of speech." (Swift) "A disposition to preserve, and an ability to improve, taken together, would be my standard of a statesman." (Burke) 4. The proportion of weights of fine metal and alloy established by authority. "By the present standard of the coinage, sixty-two shillings is coined out of one pound weight of silver." (Arbuthnot) 5. <botany> A tree of natural size supported by its own stem, and not dwarfed by grafting on the stock of a smaller species nor trained upon a wall or trellis. "In France part of their gardens is laid out for flowers, others for fruits; some standards, some against walls." (Sir W. Temple) 6. <botany> The upper petal or banner of a papilionaceous corolla. 7. <mechanics> An upright support, as one of the poles of a scaffold; any upright in framing. 8. An inverted knee timber placed upon the deck instead of beneath it, with its vertical branch turned upward from that which lies horizontally. 9. The sheth of a plow. 10. A large drinking cup. Standard bearer, an officer of an army, company, or troop, who bears a standard; commonly called colour sergeantor colour bearer; hence, the leader of any organization; as, the standard bearer of a political party. Origin: OF. Estendart, F. Etendard, probably fr. L. Extendere to spread out, extend, but influenced by E. Stand. See Extend. 1. Being, affording, or according with, a standard for comparison and judgment; as, standard time; standard weights and measures; a standard authority as to nautical terms; standard gold or silver. 2. Hence: Having a recognised and permanent value; as, standard works in history; standard authors. 3. <botany> Not supported by, or fastened to, a wall; as, standard fruit trees. Not of the dwarf kind; as, a standard pear tree. Standard candle, Standard gauge. See Candle, and Gauge. Standard solution. <chemistry> See Standardized solution, under Solution. Source: Websters Dictionary (01 Mar 1998) |
| standard atmosphere | The pressure of the atmosphere at mean sea level, equivalent to 1,013,250 dynes/cm2 or 101,325 Pa (N/m2 in the SI system), a standardised expression of the relation of barometric pressure, temperature, and other atmospheric variables as a function of altitude above sea level. (05 Mar 2000) |
| standard cell | An electrical cell having a definite known voltage; used to calibrate other electric cell's. (05 Mar 2000) |
| standard deviation | Statistical index of the degree of deviation from central tendency, namely, of the variability within a distribution; the square root of the average of the squared deviation's from the mean. A measure of dispersion or variation used to describe a characteristic of a frequency distribution. (05 Mar 2000) |
| standard dosing | An established model of administering medication. (18 Nov 1997) |
| standard error of difference | A statistical index of the probability that a difference between two sample means is greater than zero. (05 Mar 2000) |
| standard error of the mean | A statistical index of the probability that a given sample mean is representative of the mean of the population from which the sample was drawn. (05 Mar 2000) |