| protogyny | In plants, the development of the female organs before the appearance of the corresponding male products - thus inhibiting self-fertilization. (09 Oct 1997) |
|---|---|
| protohippus | <paleontology> A genus of fossil horses from the Lower Pliocene. They had three toes on each foot, the lateral ones being small. Origin: NL, from Gr. First + horse. Source: Websters Dictionary (01 Mar 1998) |
| protokylol hydrochloride | Alpha-[(alpha-Methyl-3,4-methylenedioxyphenethylamino)methyl]protocatechuyl alcohol hydrochloride;a derivative of isoproterenol with the selective beta-receptor-stimulating activity of the parent compound; it is effective orally and is more stable in the body than isoproterenol; used as a bronchodilator in the treatment of bronchial asthma and status asthmaticus. (05 Mar 2000) |
| protoleukocyte | A primitive leukocyte; a leukocyte of the bone marrow. (05 Mar 2000) |
| protolignin | <plant biology> An immature form of lignin that can be extracted from the plant cell wall with ethanol or dioxane. (18 Nov 1997) |
| protolysate | Rarely used term for a protein hydrolysate. (05 Mar 2000) |
| protolysosome | <cell biology> Primary lysosome that has not been involved in fusion with another vesicle or in digestive activity. Origin: Gr. Soma = body (18 Nov 1997) |
| protomartyr | The first martyr; the first who suffers, or is sacrificed, in any cause; applied especially. To Stephen, the first Christian martyr. Origin: LL, fr. Gr.; first + martyr: cf. F. Protomartyr. See Proto-, and Martyr. Source: Websters Dictionary (01 Mar 1998) |
| protomer | <cell biology> Subunits from which a larger structure is built. Thus the tubulin heterodimer is the protomer for microtubule assembly, G actin the protomer for F actin. Because it avoids the difficulty that arises with, for example: dimers that serve as sub units for assembly, it is a useful term that deserves wider currency. (18 Nov 1997) |
| protomerite | <zoology> The second segment of one of the Gregarinae. Origin: Proto- + -mere + -ite. Source: Websters Dictionary (01 Mar 1998) |
| protometrocyte | The ancestor cell of the protoleukocyte and protoerythrocyte, or of the cells of the leukocytic and erythrocytic series. Origin: proto-+ G. Meter, mother, + kytos, cell (05 Mar 2000) |
| protomorphic | <biology> Having the most primitive character; in the earliest form; as, a protomorphic layer of tissue. Origin: Proto- + Gr. Form. Source: Websters Dictionary (01 Mar 1998) |
| proton | <physics> An elementary atomic particle with a positive charge and a mass of about 1 amu. (09 Oct 1997) |
| proton acceptor | <chemistry> A base, an anionic substance that acceptsa proton during an acid-basereaction. (09 Oct 1997) |
| proton ATPase | <enzyme> An ion pump that actively transports hydrogen ions across lipid bilayers in exchange for ATP. Major groups are the F-type ATPases, that run in reverse to synthesise ATP in bacterial, mitochondrial and chloroplast membranes (ATP synthase) and the V-type ATPases found in intracellular vesicles with an acidic lumen and on certain epithelial cells (e.g. Kidney intercalated cells). Gastric H/K ATPase is a proton ATPase. (18 Nov 1997) |