#missense

[habbocaps]

[biol10005-blog]

Reading Frame Mutations

Mutations are any alteration in DNA sequence from a single base pair substitution, deletion, insertion or several base pairs or a major alteration in the structure of a chromosome

Mutations can occur in coding and non-coding regions of the genome.

Coding mutations can affect the gene product

Non-coding mutations can affect the expression of the gene

Coding regions of genes

Three types of base substitution mutation, defined by the effect on the gene product  

Silent: No change in the gene product

Missense: Amino acid substitution in the gene product

Nonsense: Premature termination of translation (chain termination)

Silent mutations: A change in the third base of a codon may not alter the

expression or the functioning of a gene or a gene product because of the wobble of the code.

UCA

UCG

UCC

UCU

All code for serine

Missense mutation: A mutation that changes the nucleotide sequence of a codon so that it encodes a different amino acid.

Nonsense mutation: A mutation the nucleotide sequence of a codon so that it becomes a stop codon and causes premature termination of translation.

Frameshift mutation: A mutation that removes or adds a number of nucleotides not equal to multiples of 3 (i.e mutations that disrupt the normal sequence of codons). The code is out of phase after the mutation, therefore almost all the amino acids are altered downstream.

Mutations can also include deletion or insertion where whole nucleotide can be deleted or inserted.

Illustration of concept:

[garrulousinside-blog]

Letter of _____________

Dear XYZ,

Nothing. I just miss walking to the MRT station with you. I know. I know. You got something on! So.. GOOD LUCK! JIA YOU!

Anyway, thank you for yesterday! It means a lot to me. HAHAHAHAHAHA. :D

MNO