| conformational change | <cell biology> Alteration in the shape usually the tertiary structure of a protein as a result of alteration in the environment pH, temperature, ionic strength) or the binding of a ligand (to a receptor) or binding of substrate (to an enzyme). (18 Nov 1997) |
|---|---|
| conformational map | A graphical representation in which the dihedral angle of rotation about the alpha-carbon to carbonyl-carbon bond in polypeptides is plotted against the dihedral angle of rotation about the alpha-carbon to nitrogen bond. Synonym: conformational map. (05 Mar 2000) |
| polymorphism, single-stranded conformational | Variation occurring within a species in the conformation of denatured DNA fragments. These single-stranded DNA fragments are allowed to partially renature in a way that prevents the formation of double-stranded DNA. The fragments are run on polyacrylamide gels under various conditions to detect subtle changes in migration due to altered secondary structure. The resulting bands will align themselves if the fragments are the same, but will misalign if any point mutations are present. Sscps have been used in detecting mutations in various genes, such as oncogenes, tumour suppressor genes, and genes responsible for genetic diseases. (12 Dec 1998) |
| Haworth conformational formula | <biochemistry> Of cyclic sugars, for the pyranoses, these depict those shapes (conformations) on which none, one, or two ring-atoms lie outside the plane of the ring. If there are two such atoms para to each other, they can lie 1) on opposite sides of the plane (trans), giving chair forms, or 2) on the same side of the plane (cis), giving boat forms. For beta-d-ribopyranose, the two chair forms (4C1 and 1C4) are depicted. Similarly, there are six boat conformations. If the two (trans) exoplanar atoms are meta to each other, the conformation is a skew form; if the two atoms are ortho to each other, the conformation is a half-chair form. For the furanoses, the envelope conformations have one ring-atom exoplanar. If there are three adjacent, coplanar ring-atoms (the two exoplanar ring-atoms on opposite sides of the plane), the conformations are twist forms. (05 Mar 2000) |
| single stranded conformational polymorphism | Technique for detecting point mutations in genes by amplifying a region of genomic DNA (using asymmetric PCR) and running the resulting product on a high quality gel. Single base substitutions can alter the secondary structure of the fragment in the gel, producing a visible shift in its mobility. (18 Nov 1997) |
| accumulation analysis | A technique in which an intermediate of a metabolic pathway accumulates due to selective inhibition of a particular step in that pathway or in a mutant that is deficient in a certain step. The intermediate is then isolated, analyzed, and identified. (05 Mar 2000) |
| activation analysis | <radiobiology> Method for identifying and measuring chemical elements in a sample of material. Sample is first made radioactive by bombardment with neutrons, charged particles, or gamma rays. Newly formed radioactive atoms in the sample then give off characteristic radiations (such as gamma rays) that tell what kinds of atoms are present, and how many. (09 Oct 1997) |
| actuarial analysis | The application of probability and statistical methods to calculate the risk of occurrence of any event, such as onset of illness, recurrent disease, hospitalization, disability, or death. It may include calculation of the anticipated money costs of such events and of the premiums necessary to provide for payment of such costs. (12 Dec 1998) |
| amino acid analysis | Determination and identification of amino acid content of a macromolecule, identification of a specific amino acid in macromolecules, often a mutated protein, identification and quantitation of amino acid content in blood plasma or urine; a key diagnostic aid. (05 Mar 2000) |
| analysis | <technique> The separation into component parts or elements, the act of determining the component parts of a substance. Origin: Gr. Lysis = dissolution (18 Nov 1997) |
| analysis of variance | A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable. (12 Dec 1998) |
| base sequence analysis | <molecular biology> A method, sometimes automated, for determining the base sequence. (09 Oct 1997) |
| bite analysis | A study of the relations of the occlusal surfaces of opposing teeth and their effect upon related structures. Synonym: bite analysis. (05 Mar 2000) |
| blood gas analysis | <investigation> A test which analyses arterial blood for oxygen, carbon dioxide and bicarbonate content in addition to blood pH. Used to test the effectiveness of respiration. (27 Sep 1997) |
| bradykinetic analysis | The analysis of a movement by means of slow cinematography. (05 Mar 2000) |