Why must a copy of mRNA be made during transcription?

1 Answer
Jun 1, 2018

A copy of mRNA must be made during transcription to effect translation of protein molecule with specific sequence of amino acids on ribosomes as per the codons in DNA molecule.

Explanation:

The mRNA molecule has specific sequence of codons complementary to codon sequence in DNA molecule. DNA does not move out of the nucleus.

mRNA transcribed comes out of the nucleus and moves to the ribosome, the site of protein synthesis.

The amino acids are brought to the ribosome as per the sequence of codoms in mRNA by tRNAs from cytoplasm.

There is specific tRNA for every amino acid. tRNAs combine with their specific amino acids to form amino-tRNA complex. tRNA has complementary codon sequence to the mRNA codon sequence of its specific amino acid.

Thus the specific amino acids are brought to the site of protein synthesis by tRNA .

Thus the mRNA must be made during transcription because mRNA has complementary codon sequence to the codon sequence of tRNA that form complex with amino acids in cytoplasm.