Transcription is the process of transcribing DNA so that a copy can be taken away and used as a template for making proteins.
The hydrogen bonds between the two lengths of DNA are forced apart and a length of ribonucleic acid, or RNA, is formed.
In RNA there is no T (thymine), instead there is a different nucleotide, Uracil (U), which pairs with A.
Each set of 3 RNA base units forms a codon.
Codons are
1. Non overlapping
2. Degenerate
3. Triplet code
4. Codes for one amino acid
This first type of RNA is messenger RNA or mRNA
Links
Gene Expression- Transcription
Interactive tutorial
Molecular Biology Notebook
extension
New Scientist - Biology's Master Chefs