Question

Define transcription.

Answer 1

Hint:There are many functions carried out inside the cells. One of the processes is transfer of genetic materials to form proteins. And as we know protein is the essential product for the proper functioning of cells.

Complete answer:
Before answer this question we should know about the central dogma of life. The process in which the DNA is instructed and converted into functional product is termed as central dogma of life. It explains the transfer of genetic materials from DNA to RNA to make a functional product called protein the other name of this process is gene expression. The two stages of this gene expression process are; transcription and translation. In, transcription, the DNA information from each cell is converted to RNA messenger. The RNA messenger, during the translation process, converts into specific proteins.

Now, let’s understand the transcription process in detail; transcription is a process in which the DNA is converted to RNA as mentioned above. The genetic information from the DNA also gets transferred into the RNA molecules. Though the RNA consists of the same genetic information it is not identical to the DNA segment as its sequence is complementary to the DNA template. The transcription process is carried out with the help of an enzyme called RNA polymerase and some accessory proteins are also involved that are called transcription factors. The transcription factors bind to specific DNA sequences to enhance and promote the sequence to recruit the RNA polymerase enzyme. The RNA polymerase and the transcription factor form a complex that is termed as transcription initiation complex. This complex involves the beginning of mRNA synthesis by matching complementary bases to the original DNA strand. The mRNA molecules elongate and after the completion of synthesis the process gets terminated. The newly produced mRNA copies of the gene; this is further used as a blueprint for the protein synthesis.

Note:The RNA polymerase enzyme involved in the transcription process can only synthesize the RNA template from 5’ to 3’ direction. This feature is similar to the DNA polymerase enzyme used in the replication process and because of this feature the complementary DNA produces discontinuous fragments of RNA that is called oka-zaki fragments.