- Making an RNA copy from a sequence of DNA (a gene). Transcription is the first step in gene expression.
* * *Transfer of genetic code information from one kind of nucleic acid to another, especially with reference to the process by which a base sequence of messenger RNA is synthesized (by an RNA polymerase) on a template of complementary DNA.- reverse t. reversal of the normal pattern of t. (from DNA to RNA); the effective means is the viral enzyme reverse transcriptase.
* * *tran·scrip·tion tran(t)s-'krip-shən n the process of constructing a messenger RNA molecule using a DNA molecule as a template with resulting transfer of genetic information to the messenger RNA compare REVERSE TRANSCRIPTION, TRANSLATIONtran·scrip·tion·al -shnəl, -shən-əl adjtran·scrip·tion·al·ly -ē adv
* * *n.the process in which the information contained in the genetic code is transferred from DNA to RNA: the first step in the manufacture of proteins in cells. See messenger RNA, translation.
* * *trans·crip·tion (trans-kripґshən) [L. transcriptio transfer, copy] the process by which a single-stranded RNA with a base sequence complementary to one strand of a double-stranded DNA is synthesized. The enzymes involved are called DNA-dependent RNA polymerases (see under polymerase).
Transcription. Binding of the RNA polymerase at a specific site on DNA to be transcribed (A) is followed by unwinding of a region of the DNA helix and initiation of transcription in a 5′ to 3′ direction (B), producing an RNA transcript complementary to, and hydrogen-bonded with, the template strand of the DNA. The transcript elongates as the polymerase proceeds down the DNA (C), with the helix unwinding before and rewinding after it.
Medical dictionary. 2011.