Lecture 36-Mutation

Lecture 36-Mutation - Lecture 36- Mutation Note: We skipped...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 36- Mutation Note: We skipped lecture 35. Oncomir slides are not testable. Mutation -Mutation is defined as “a heritable change in the double-stranded sequence of DNA” -Most mutation begins as “DNA damage” in which only one strand or the other is affected -If unrepaired, such damage can lead to double-stranded changes in the DNA sequence Proof-reading -If, for example, polymerase is reading the strand and by mistake polymerase puts in a C base with an A, it has the ability to “proof-read”, to take out/excise the base that is wrong and put in the right one -DNA polymerases can do this, but not RNA polymerases -Gives DNA polymerases the ability to take a second chance -When the wrong base pair is put in, it is called a “mismatch”, NOT a mutation Excision Repair -Different mismatch; polymerase failed to proof-read, mismatch persists -This is also not a mutation, just damage to the DNA -Enzymes look for these mismatches (recognisable by the uncharacteristic distance between the base pair and thus no hydrogen bonding) and cut out the chunk with the mismatch and
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

Lecture 36-Mutation - Lecture 36- Mutation Note: We skipped...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online