Lecture notes from Imperial College London, Medical Biosciences BSc, 2nd year, genetics and genomics (GEN) module.
Our DNA is under constant threat of being damaged by exogenous and endogenous insults. We have some mechanisms that provide protection from these insults, but there are limits to wh...
Protecting the Genome
- DNA repair can’t prevent the accumulation of DNA damage, part of the normal ageing process
Causes of DNA damage
- endogenous chemicals
=> free radicals (bi-products of normal metabolism: oxidative phosphorylation) can react with DNA
m with an impaired electron
ex: reactive oxygen species (ROS)
oxidise DNA (gain O/ lose e-)
=> spontaneous hydrolysis (use of H2O to break down the bonds of a m)
=> alkylation (alkylating agents)
short wavelength
- ionising radiations (IR):
en
=> electromagnetic waves (X-rays/ UVB light at 295-300nm damage DNA in skin cells)
=> atomic or subatomic particles (unstable isotopes in rocks: Uranium-235)
=> damage DNA directly or by generating ROS from H2O
=> chr segregation failure: kinetochores (centromeric p)
fail to attach to spindle => cells with 2 copies/ none
insertion-deletion loops (IDLs)
Avoid the causes of genome damage
- can’t avoid IR but can avoid tobacco, fumes...
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller lisaribau. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R187,07. You're not tied to anything after your purchase.
