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Abstract
Nucleic acids DNA and RNA are the carriers of genetic information. RNA is similar in structure to DNA, however the sugar in RNA is ribose rather than deoxyribose and the base pairs contain uracil instead of thymine. Several types of RNA are recognized : mRNA which carries the genetic information, rRNA which is a structural support for protein synthesis and tRNA which is connector.
The first step in communication of genetic information from the nucleus to the cytoplasm is the transcription of DNA into messenger RNA which proceeds via multiple stages : initiation - elongation - termination. Transcription factors help determine which genes for each type of cell are transcribed. Promoters play an important role in determining the level of transcription of different genes. Enhancers increase the transcription initiation. After splicing the mature mRNA is transported from the nucleus to the cytoplasm, where it is translated into a polypeptide chain.