| nucleoplasmic index | The quotient of the nuclear volume divided by the cytoplasmic volume. (05 Mar 2000) |
|---|---|
| nucleoplasmin | <protein> First protein to be described as a molecular chaperone, major function seems to be in assembly of nucleosomes. (18 Nov 1997) |
| nucleopolyhedrovirus | A genus of the family baculoviridae, subfamily eubaculovirinae, characterised by the formation of crystalline, polyhedral occlusion bodies in the host cell nucleus. The type species is autographa californica nucleopolyhedrovirus. (12 Dec 1998) |
| Nucleopore filter | Filter of defined pore size made by etching a polycarbonate filter that has been bombarded by neutrons, the extent of etching determining the pore size. Very thin, with neat circular holes going right through the membrane, not a complex meshwork like micropore filters. (18 Nov 1997) |
| nucleoprotein | A complex of protein and nucleic acid, the form in which essentially all nucleic acids exist in nature; chromosomes and viruses are largely nucleoprotein. (05 Mar 2000) |
| nucleoproteins | Structures containing both nucleic acid and protein. Examples are chromatin, ribosomes, certain virus particles. (18 Nov 1997) |
| nucleoreticulum | The intranuclear network of chromatin or linin. Origin: nucleo-+ L. Reticulum, dim. Of rete, net (05 Mar 2000) |
| nucleorrhexis | Fragmentation of a cell nucleus. Origin: nucleo-+ G. Rhexis, rupture (05 Mar 2000) |
| nucleosidase | <enzyme> Catalyses hydrolysis of n-ribosyl-purine into a purine and d-ribose Registry number: EC 3.2.2.1 Synonym: purine nucleoside hydrolase, guanosine hydrolase (26 Jun 1999) |
| nucleosidases | <enzyme> Registry number: EC 3.2.2. (12 Dec 1998) |
| nucleoside | <biochemistry> Purine or pyrimidine base linked glycosidically to ribose or deoxyribose, but lacking the phosphate residues that would make it a nucleotide. Ribonucleosides are adenosine, guanosine, cytidine and uridine. Deoxyribosides are deoxyadenosine, deoxyguanosine, deoxycytidine and deoxythymidine (the latter is almost universally referred to as thymidine). (18 Nov 1997) |
| nucleoside analogue | A synthetic molecule that resembles a naturally occuring nucleoside, but that lacks a bond site needed to link it to an adjacent nucleotide. (09 Oct 1997) |
| nucleoside bisphosphate | A nucleoside that carries two independent (i.e., not linked to each other) phosphoric residues. Compare: nucleoside diphosphate. (05 Mar 2000) |
| nucleoside deaminases | <enzyme> Catalyze the hydrolysis of nucleosides with the elimination of ammonia. Registry number: EC 3.5.4 (12 Dec 1998) |
| nucleoside diphosphate | The pyrophosphoric ester of a nucleoside, i.e., a nucleoside in which the H of one of the ribose hydroxyls (usually the 5') is replaced by a pyrophosphoric (diphosphoric) radical; e.g., adenosine 5'-diphosphate. Compare: nucleoside bisphosphate. (05 Mar 2000) |