| peptide initiation factors | Protein factors uniquely required during the initiation phase of protein synthesis. (12 Dec 1998) |
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| initiation factors | The set of catalytic proteins required, in addition to mRNA and ribosomes, for protein synthesis to begin. In bacteria three distinct proteins have been identified: if 1 (8 kD), IF 2 (75 kD) and IF 3 (30 kD). at least 6-8 proteins have been identified in eukaryotes. IFs 1 and 2 enhance the binding of initiator tRNA to the initiation complex. (18 Nov 1997) |
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| peptide chain initiation | The process whereby the formation of a peptide chain is started. This process requires (1) the 30s subunit, (2) the mRNA coding for the polypeptide to be made, (3) met-trnai, (4) initiation factors, and (5) GTP. (12 Dec 1998) |
| peptide elongation factors | Protein factors uniquely required during the elongation phase of protein synthesis. (12 Dec 1998) |
| peptide termination factors | Proteins that are exclusively involved in the termination reactions of protein synthesis on the ribosome. (12 Dec 1998) |
| initiation | 1. The first stage of tumour induction by a carcinogen; subtle alteration of cells by exposure to a carcinogenic agent so that they are likely to form a tumour upon subsequent exposure to a promoting agent (promotion). 2. Starting point of replication or translation in macromolecule biosynthesis. 3. Start of chemical or enzymatic reaction. (05 Mar 2000) |
| initiation codon | The codon 5' AUG in mRNA, at which polypeptide synthesis is started. It is recognised by formylmethionyl tRNA in bacteria and by methionyl tRNA in eukaryotes. (18 Nov 1997) |
| initiation complex | Complex between mRNA, 30S ribosomal subunit and formyl methionyl tRNA that requires GTP and initiation factors to function. (18 Nov 1997) |
| initiation factor | One of several soluble proteins involved in the initiation of protein or RNA synthesis. (05 Mar 2000) |
| initiation tRNA | TRNA in prokaryotes containing a formyl-methionyl residue that initiates translation. Synonym: formyl-methionyl-tRNA, starter tRNA. (05 Mar 2000) |
| tumour initiation | <cell biology, oncology> First stage of tumour development. See: tumour progression. (18 Nov 1997) |
| age factors | Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from aging, a physiological process, and time factors which refers only to the passage of time. (12 Dec 1998) |
| bacteriocin factors | Bacterial plasmid's responsible for the elaboration of bacteriocins. Synonym: bacteriocin factors, bacteriocinogens. (05 Mar 2000) |
| B-cell differentiation/growth factors | Various substances, usually obtained from the supernatant of T-cell cultures, such as interleukin 4, 5, and 6. These substances are necessary for B-cell growth, maturation, and differentiation into plasma cells or B memory cells. (05 Mar 2000) |
| biological factors | Compounds made by living organisms. They have biological or physiological activities. (12 Dec 1998) |
| biotic factors | Environmental factor's or influences resulting from the activities of living organisms, as contrasted to those resulting from climatic, geological, or other factor's. (05 Mar 2000) |