Question

	Why does the addition or removal of a single nucleotide have a dramatic effect on a protein's function? What type of mutation is this?
	A mutation occurs in the portion of a gene that makes a protein. This mutated protein has the same amino acid sequence as the normal protein. Explain how this could happen.

Answer 1

If addition or removal of one single nucleotide happens it result s in full alteration of the amino acid composition of the protein and thus altered 3 d structure of protein because it is dependent on the amino acids sequence of the protein.

This mutation is called frame-shift mutation because in this case all the codons become changes because if you add one nucleotide it will make new codon which will then code different amino acids and thus different protein will be translated and it will be nonfunctional.

Like suppose, one mRNA sequence is. 5' AUG AUU UAA 3' AND IT CODES FOR METHIONINE -ALANINE -TRYPTOPHAN( SUPPOSE BUT IT IS ARBITRARY).

NOW IF YOU ADD ONE ADENINE NEXT TO FIRST ADENINE THEN TGE MRNA SEQUENCE WILL BE 5'AAU GAU UUA A 3' ,.SO THIS SEQUENCE IS DIFFERENT AND DIFFERENT AMINO ACID WILL BE CODED.

NEXT , IF MUTATION SHOW NO EFFECT THEN IT IS CALLED NEUTRAL MUTATION LIKE IF ONE NUCLEOTIDE OF ONE CODON HAS BEEN REPLACED BY ONE DIFFERENT NUCLEOTIDE AT ITS 3RD POSITION , THEN ACCORDING TO WOOBLE HYPOTHESIS, THE ENCODED AMINO ACID WILL BE SAME AS FOR EXAMPLE if one codon is GGG and last Guanine is replaced by Adenine then also it will codes alanine as when GGG.

SO THIS MUTATION WILL HAVE NO EFFECT.