The Process of Transcription: From DNA to mRNA and Protein Synthesis

the process where the DNA sequence is copied into mRNA

The process we are referring to is called transcription

The process we are referring to is called transcription. Transcription involves the synthesis of a complementary RNA molecule from a DNA template. The resulting RNA molecule is called messenger RNA (mRNA) because it carries the genetic information from the DNA to the ribosomes, where it serves as a template for protein synthesis.

Let’s delve into the steps involved in transcription:

1. Initiation: Transcription begins with the binding of an enzyme called RNA polymerase to a specific region of the DNA called the promoter. The promoter is typically located near the beginning of a gene. The RNA polymerase recognizes and binds to the promoter, marking the starting point for transcription.

2. Elongation: Once the RNA polymerase is bound to the promoter, it starts to unwind and separate the DNA strands. The RNA polymerase then incorporates nucleotides to form a complementary RNA strand using one of the DNA strands as a template. The RNA is synthesized in the 5′ to 3′ direction, meaning that new nucleotides are added to the 3′ end of the growing RNA molecule.

3. Termination: Transcription continues until the RNA polymerase reaches a specific termination sequence on the DNA template. This signals the end of transcription, and the newly synthesized mRNA molecule is released. The DNA strands rejoin, and the RNA polymerase detaches from the DNA template.

It is important to note that only one DNA strand, known as the template strand or antisense strand, is transcribed into mRNA. The other DNA strand, known as the coding strand or sense strand, has the same sequence as the newly synthesized mRNA molecule, except that the bases are represented by thymine (T) instead of uracil (U) in RNA.

After transcription, the mRNA molecule undergoes further processing in eukaryotic cells before it is ready for translation into protein. This includes the addition of a cap structure at the 5′ end and a poly-A tail at the 3′ end, as well as the removal of non-coding regions called introns through a process called splicing.

In summary, transcription is the process by which the DNA sequence is copied into a complementary mRNA molecule. This mRNA carries the genetic information from the DNA to the ribosomes, where it directs the synthesis of proteins.

More Answers: