| RuDP carboxylase | <enzyme> A copper protein that catalyses the formation of 2 moles of 3-phosphoglycerate from ribulose 1,5-biphosphate in the presence of carbon dioxide and is responsible for carbon dioxide fixation in photosynthesis. Carbon dioxide is combined with ribulose diphosphate to give two molecules of 3 phosphoglycerate, as part of the Calvin Benson cycle. It is the sole carbon dioxide fixing enzyme in C3 plants and collaborates with PEP carboxylase in carbon dioxide fixation in C4 plants. In the presence of oxygen the products of the reaction are one molecule of phosphoglyceric acid and one molecule of phosphoglycolic acid. The latter is the initial substrate for photorespiration and this oxygenase function occurs in C3 plants where the enzyme is not protected from ambient oxygen, in C4 plants the enzyme acts exclusively as a carboxylase since it is protected from oxygen. Also called Fraction 1 protein, the major protein of leaves. Chemical name: 3-Phospho-D-glycerate carboxy-lyase (dimerizing) Registry number: EC 4.1.1.39 (12 Dec 1998) |
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| rue | 1. <botany> A perennial suffrutescent plant (Ruta graveolens), having a strong, heavy odour and a bitter taste; herb of grace. It is used in medicine. "Then purged with euphrasy and rue The visual nerve, for he had much to see." (Milton) "They [the exorcists] are to try the devil by holy water, incense, sulphur, rue, which from thence, as we suppose, came to be called herb of grace." (Jer. Taylor) 2. Bitterness; disappointment; grief; regret. Goat's rue. See Goat. Rue anemone, a pretty springtime flower (Thalictrum anemonides) common in the United States. Wall rue, a little fern (Asplenium Ruta-muraria) common on walls in Europe. Origin: F. Rue, L. Ruta, akin to Gr.; cf. AS. Rde. Source: Websters Dictionary (01 Mar 1998) |
| ruff | 1. A muslin or linen collar plaited, crimped, or fluted, worn formerly by both sexes, now only by women and children. "Here to-morrow with his best ruff on." (Shak) "His gravity is much lessened since the late proclamation came out against ruffs; . . . They were come to that height of excess herein, that twenty shillings were used to be paid for starching of a ruff." (Howell) 2. Something formed with plaits or flutings, like the collar of this name. "I reared this flower; . . . Soft on the paper ruff its leaves I spread." (Pope) 3. An exhibition of pride or haughtiness. "How many princes . . . In the ruff of all their glory, have been taken down from the head of a conquering army to the wheel of the victor's chariot!" (L'Estrange) 4. Wanton or tumultuous procedure or conduct. "To ruffle it out in a riotous ruff." (Latimer) 5. A low, vibrating beat of a drum, not so loud as a roll; a ruffle. 6. <machinery> A collar on a shaft ot other piece to prevent endwise motion. 7. <zoology> A set of lengthened or otherwise modified feathers round, or on, the neck of a bird. 8. <zoology> A limicoline bird of Europe and Asia (Pavoncella, or Philommachus, pugnax) allied to the sandpipers. The males during the breeding season have a large ruff of erectile feathers, variable in their colours, on the neck, and yellowish naked tubercles on the face. They are polygamous, and are noted for their pugnacity in the breeding season. The female is called reeve, or rheeve. A variety of the domestic pigeon, having a ruff of its neck. Origin: Of uncertain origin: cf. Icel. Rfinn rough, uncombed, Pr. Ruf rude, rough, Sp. Rufo frizzed, crisp, curled, G. Raufen to pluck, fight, rupfen to pluck, pull, E. Rough. Cf. Ruffle to wrinkle. Source: Websters Dictionary (01 Mar 1998) |
| ruffe | <zoology> A small freshwater European perch (Acerina vulgaris). Synonym: pope, blacktail, and stone, or striped, perch. Origin: OE. Ruffe. Source: Websters Dictionary (01 Mar 1998) |
| ruffed | Furnished with a ruff. Ruffed grouse, a species of lemur (lemur varius) having a conspicuous ruff on the sides of the head. Its colour is varied with black and white. Synonym: ruffed maucaco. Source: Websters Dictionary (01 Mar 1998) |
| ruffin | Disordered. "His ruffin rainment all was stained with blood." (Spenser) See: Ruffian. Source: Websters Dictionary (01 Mar 1998) |
| Ruffini's corpuscles | Sensory end-structures in the subcutaneous connective tissues of the fingers, consisting of an ovoid capsule within which the sensory fibre ends with numerous collateral knobs. (05 Mar 2000) |
| Ruffini, Angelo | <person> Italian histologist, 1864-1929. See: Ruffini's corpuscles, flower-spray organ of Ruffini. (05 Mar 2000) |
| ruffle | 1. <cell biology> Projections at the leading edge of a crawling cell. In time lapse films the active edge appears to ruffle. The protrusions are apparently supported by a microfilament meshwork and can move centripetally over the dorsal surface of a cell in culture. 2. <zoology> The connected series of large egg capsules, or oothecae, of any one of several species of American marine gastropods of the genus Fulgur. See Ootheca. Ruffle of a boot, the top turned down, and scalloped or plaited. 3. To make into a ruff; to draw or contract into puckers, plaits, or folds; to wrinkle. That which is ruffled; specifically, a strip of lace, cambric, or other fine cloth, plaited or gathered on one edge or in the middle, and used as a trimming; a frill. 4. A state of being ruffled or disturbed; disturbance; agitation; commotion; as, to put the mind in a ruffle. 5. To oughen or disturb the surface of; to make uneven by agitation or commotion. "The fantastic revelries . . . That so often ruffled the placid bosom of the Nile." (I. Taylor) "She smoothed the ruffled seas." (Dryden) Origin: From Ruff a plaited collar, a drum beat, a tumult: cf. OD. Ruyffelen to wrinkle. Source: Websters Dictionary (01 Mar 1998) |
| rufigallic | <chemistry> Pertaining to, or designating, an acid which is obtained from gallic acid as a brown or red crystalline substance, and is related to rufiopin and anthracene. Source: Websters Dictionary (01 Mar 1998) |
| rufiopin | <chemistry> A yellowish red crystalline substance related to anthracene, and obtained from opianic acid. Origin: L. Rufus reddish + opianic. Source: Websters Dictionary (01 Mar 1998) |
| rufol | <chemistry> A phenol derivative of anthracene obtained as a white crystalline substance, which on oxidation produces a red dyestuff related to anthraquinone. Origin: L. Rufus reddish + -ol. Source: Websters Dictionary (01 Mar 1998) |
| rufous | Synonym: erythristic. Origin: L. Rufus, reddish (05 Mar 2000) |
| rufous albinism | A pigmentary anomaly of blacks, characterised by red or yellow-red hair colour, copper-red skin, and often by dilution of iris pigment. Synonym: rufous albinism. Origin: G. Xanthos, yellowish (05 Mar 2000) |
| ruft | <medicine> Eructation; belching. Source: Websters Dictionary (01 Mar 1998) |