orortris(hydroxymethyl)aminomethane; 2‐amino‐2‐hydroxymethyl‐1,3‐propanediol; a compound widely used as a biological buffer substance in the pH range 7–9; pKa (20 °C) = 8.3; pKa (37 °C) = 7.82.
A pentose sugar found in plant polysaccharides. It is an epimer of ribose and is found in cytosine arabinoside.
or5,5‐diethylbarbituric acid; 5‐diethylmalonylurea; 5,5‐diethyl‐2,4,6(1H,3H,5H)‐pyrimidinetrione; a long‐acting depressant of the central nervous system, widely used as a buffer substance; pKa = 7.98 ...
(isohaemagglutinin) n. one of the antibodies occurring naturally in the plasma that cause agglutination of red blood cells of a different group.
An enzyme that catalyses the hydrolysis of RNA, resulting in the formation of mono- and oligonucleotides.
A substance that causes an immune response. Foreign proteins and glycoproteins generally make the most potent immunogens. See antigen.
n. chromosome material (see chromatin) that stains most deeply during mitosis and represents the major genes. Compare heterochromatin.
The part of a cell of a bacterium (i.e. a prokaryotic cell) that contains the genetic material DNA and therefore controls the activity of the cell. It corresponds to the nucleus of the more advanced ...
A measure of enzyme activity, normally expressed as the number of moles of substrate transformed into one or more products per mole of enzyme.
A monosaccharide or its derivative that contains a ketone group.
A monosaccharide in which the (potential) carbonyl group is terminal (i.e. aldehydic). The term is frequently modified to indicate the number of carbon atoms in the chain, as in aldotriose, ...
A device for detecting high-energy charged particles via the Cerenkov radiation they generate. This radiation, which appears as a predominantly bluish light, can be detected using photomultiplier ...
A suspension of small solid particles produced in a liquid by chemical reaction.
A receptor on one of the neurons responsible for feelings of pain and pleasure that binds to opioids.
A nucleoside consisting of one uracil molecule linked to a dribose sugar molecule. The derived mucleotide uridine diphosphate (UDP) is important in carbohydrate metabolism.Uridine
A carbohydrate-digesting enzyme, produced in the brush border of the small intestine, that breaks down the disaccharide sucrose into the monosaccharides glucose and fructose.
The cause of poliomyelitis (infantile paralysis). It is a positive-stranded RNA virus with a 6.1 kb genome. Enormous polysomes (q.v.) containing 60 or more ribosomes occur in infected cells. The ...
Any of various compounds derived from benzene and containing C=O groups in an unsaturated ring. An example is plastoquinone.
An aliphatic, polar (see polar molecule) alpha-amino acid. It is often associated with the active site of an enzyme.
One of a group of haemoproteins, which are classified into four groups designated a, b, c, and d. They function as electron carriers in a variety of redox reactions in virtually all aerobic organisms.