Answer to Question #287673 in Genetics for Minahil Dar

Question

The gene for the human protein albumin spans a

chromosomal region 25,000 nucleotide pairs (25 kilo-

bases, or kb) long from the beginning of the protein-coding sequence to the end of the protein-

coding sequence, but the messenger RNA for this protein is only 2.1 kb long. What do you think accounts

for this huge difference?

Answer 1

The huge difference is accounted for by the number of amino acid chains contained in mRNA and proteins, in that proteins contain many (twenty-one) chains of amino acid linked together. In contrast, mRNA has just one chain of amino acids.

Explanation:

During transcription, coded genetic information is copied into mRNA. The information in mRNA is then translated into chains of amino acids. Further, these amino acid chains are linked by folding into various shapes such as helices and zigzags forming proteins. Hence proteins have many amino acid chains compared to mRNA, with one amino acid chain.