The changes will affect amino acid as follows:
a) The DNA sequence will shift forward to accommodate the new base pair and new triplet codon will make different amino acid sequence.
b) The DNA sequence will shift to backward and the base pair next to deleted one will for triplet and code for different amino acid.
c) The shuffling or substitution of nucleotide will code for different amino acid which is probably not the part of the protein.
Explanation:
DNA sequence in responsible for the formation proteins in the body. DNA sequence also called gene carry the genetic information of the organism.
DNA undergoes transcription to form mRNA which have both coding (exon) and non-coding sequence (introns). After splicing exons come join in to get ready for translation. The mRNA sequence is read by tRNA and each triplet codes fro a amino acid to be brought to the growing polypeptide chain.
The genetic code table decides which amino acid to be brought by tRNA, coded by mRNA.
A mutation leads to change in DNA sequence which eventually changes mRNA and consequently the amino acid.
a) Addition of a nucleotide is termed point mutation. The DNA sequence gets shifted forward and codon reading is ultimately wrong as the added nucleotide would become triplet codon and form different amino acids.
b) The deletion of nucleotide will cause backward shifting of the DNA frame. It would form triplet codon with other nucleotides which codes for different amino acids.
c) Suppose thymine gets replaced with guanine in the DNA sequence it will change the acid sequence and entire protein. Substitution mutation are caused by shuffling or exchange of base pair in a gene.
