Answer:
Please find the explanation of the nucleotide change below
Explanation:
Mutation is any change that occurs to the nucleotide sequence of a gene. According to this question, a substitution mutation which causes the Serine amino acid to change to Proline amino acid in the cytochrome b5 reductase enzyme is described.
A substitution mutation is a type of mutation in which one or more nucleotide base is replaced by another. The mRNA codons that specify Serine and Proline amino acids are as follows:
Serine: UCU, UCC, UCA, UCG, AGU, AGC
Proline: CCU, CCC, CCA, CCG
Based on the observation of these bases, URACIL BASE in the first four listed codons for serine amino acid is replaced by CYTOSINE BASE. i.e.
UCU (serine) -> CCU (proline)
UCC (serine) -> CCC (proline)
UCA (serine) -> CCA (proline)
UCG (serine) -> CCG (proline)
Notice that these base substitutions (U-C) occur in the 1st position of the codon.
