Question

Consider the given data of a hypothetical small portion of mRNA that codes for a functional polypeptide chain and answer the questions that follow:
mRNA Sequence: 5’– UCAUUAACCCAGAUCUUCUUAAAAGGA –3’
How many amino acids will be formed from the given codons, if substitution of ‘U’ by ‘C’ takes place at the 5th codon? Explain your answer.

Hint:

Substitutions in codons can change amino acids, altering protein structure and function.

Answer 1

The sequence changes to 5’- UCAUUAACCCAGACCUUCUUAAAAGGA-3’. The 5th codon changes from UCU to CCU, coding for Proline instead of Serine. Amino acids = Total codons – Stop codon = 8.