Canadian Medical Guide > Chemicals and Drugs > Nucleic Acids, Nucleotides, and Nucleosides > Nucleic Acids > RNA Terms and Definitions




RNA

Medical Definition: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Guide Notes: /immunol: consider also IMMUNE RNA MANIPULATION see IMMUNOTHERAPY, ACTIVE
CAS Type 1 Name: CAS Number: 63231-63-0
RNA Categories.
Canadian Medical Guide Definition RNA, Archaeal - Ribonucleic acid in archaea having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Bacterial - Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Chloroplast - Ribonucleic acid in chloroplasts having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Double-Stranded - RNA consisting of two strands as opposed to the more prevalent single-stranded RNA. Most of the double-stranded segments are formed from transcription of DNA by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. Some double-stranded segments of RNA are normal in all organisms.
Canadian Medical Guide Definition RNA, Fungal - Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Helminth - Ribonucleic acid in helminths having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Messenger - RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Canadian Medical Guide Definition RNA, Neoplasm - RNA present in neoplastic tissue.
Canadian Medical Guide Definition RNA, Nuclear - RNA molecules found in the nucleus either associated with chromosomes or in the nucleoplasm.
Canadian Medical Guide Definition RNA, Plant - Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Protozoan - Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.
Canadian Medical Guide Definition RNA, Ribosomal - The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)
Canadian Medical Guide Definition RNA, Satellite - Small, linear single-stranded RNA molecules functionally acting as molecular parasites of certain RNA plant viruses. Satellite RNAs exhibit four characteristic traits: (1) they require helper viruses to replicate; (2) they are unnecessary for the replication of helper viruses; (3) they are encapsidated in the coat protein of the helper virus; (4) they have no extensive sequence homology to the helper virus. Thus they differ from SATELLITE VIRUSES which encode their own coat protein, and from the genomic RNA; (=RNA, VIRAL); of satellite viruses. (From Maramorosch, Viroids and Satellites, 1991, p143)
Canadian Medical Guide Definition RNA, Transfer - The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
Canadian Medical Guide Definition RNA, Untranslated - RNA which does not code for protein but has some enzymatic, structural or regulatory function. Although ribosomal RNA; (RNA, RIBOSOMAL) and transfer RNA; (RNA, TRANSFER) are also untranslated they are not included here.
Canadian Medical Guide Definition RNA, Viral - Ribonucleic acid that makes up the genetic material of viruses.

RNA Medical Definitions and Terms

CANADIAN MEDICAL GUIDE

Thank you for visiting Canadian Medical Guide .com





Wildlife On Video »

Canadian Medical Guide Canada's Great Outdoors
Tour Canadian Rockies »
Book Banff »
Book Jasper »
Maligne Lake Boat Cruise »
Gondola Banff »
Hike Jasper »
Jasper Columbia Icefield »