DNA repair and Maintenance of Genome Stability Flashcards
What is a transition mutation?
Pyrimidine to Pyrimidine
T->C
What is a transversion mutation?
Pyrimidine to purine
T->G
Types of pyrimidine
Cytosine
Thymine
Types of purines
Adenine
Guanine
What can induce DNA damage
UV light
Give an example of when can mutations be advantageous?
When the cells only survive in arginine, they can mutate so that you can live without arginine present
What is a nucleotide?
A bass + sugar + phosphate backbone
what can point mutations cause?
stop codons
silent mutations
point mutations - effects gene function
How is DNA read?
triplet codons
What are the consequences of mutations?
Gene amplification Broken genes Fused genes Altered genes Missing code Damaged gene
What causes mutations?
Luck Inherited predisposition Environmental: External e.g. smoking Internal e.g. free the metabolised oxygen which attack the DNA
Know the types of DNA damage
Nucleotide damage (UV light) e.g. pyrimidine dimer
Abasic site (hydrolysis)
Base damage:
- Cytosine deamination e.g. uracil
- Alkylating agents e.g. 06 methyl adenine
- Reactive oxygen e.g. oxoguanine
cause does depurination cause?
spontaneous reaction with water
what is the consequence of depurination?
base loss
What causes mutations?
Replication, a base change does not cause the mutation, it is the replication with the base change
What causes deamination?
Spontaneous, specialist deaminases