Suppose the amino acid coding region in an mRNA is 1200 nucleotides long. How long is the protein in terms of amino acid number?

A. 1200 amino acids
B. 600 amino acids
C. 400 amino acids
D. 300 amino acids



Answer :

To determine the length of the protein in terms of the number of amino acids given that the amino acid coding region in a mRNA is 1200 nucleotides long, we need to understand how nucleotide sequences correspond to amino acids.

Each amino acid in a protein is encoded by a sequence of three nucleotides, known as a codon. Therefore, to find out the number of amino acids that can be encoded by a given number of nucleotides, we divide the total number of nucleotides by the number of nucleotides in one codon (which is 3).

Given:
- Total number of nucleotides = 1200

Let's calculate the number of amino acids:
[tex]\[ \text{Number of amino acids} = \frac{\text{Total number of nucleotides}}{\text{Number of nucleotides per codon}} \][/tex]

[tex]\[ \text{Number of amino acids} = \frac{1200}{3} \][/tex]

[tex]\[ \text{Number of amino acids} = 400 \][/tex]

Therefore, the number of amino acids that would be encoded by the 1200 nucleotides long mRNA is 400.

So the correct answer is:
C. 400 amino acids