Synthesis of Ribonucleic Acid (RNA) from Deoxyribonucleic Acid (DNA) is called transcription. Transcription is one of the most important processes for living beings. Through transcription, the genetic information stored in DNA is expressed. To carry out the transcription process, one of the two DNA strands serves as a template (non-coding or sense strand) and another that does not participate in transcription is called the coding strand or antisense strand. The template strand produces working copies of RNA molecules.
Some interesting facts behind transcription
Transcription is selective: The entire molecule of DNA is not expressed in transcription. Only some selected regions of DNA synthesized RNA. For certain other DNA regions, there may be no transcription at all. The exact region for the selective transcription is yet unknown. This may be due to some inbuilt signals in the DNA molecule.
Primary transcript: The product formed in transcription is referred to as primary transcript. Most often, the primary RNA transcripts are inactive. They undergo certain alterations through some processes like splicing, terminal additions, base modifications, etc.
Post-transcriptional modification: As discussed above, freshly formed RNA molecules are inactive. To make them functional, they undergo some modifications after the transcription. This modification is often referred to as post-transcriptional modification. Such modification processes are- splicing, terminal additions, base modifications, etc.
Prokaryotic transcription
Transcription in prokaryotic organisms is much simpler than eukaryotic ones.