week 7

Question 1

how are thymine dimers caused?

Answer 1

UV radiation
- this is super problematic
- also bc it was caused by something this is an induced mutation

Question 2

what are the 2 types of mutations?

Answer 2

spontaneous and induced

Question 3

5 spontaneous mutations

Answer 3

1. tautomerization (keto->enol)
2. transition (purine -> purine)
3. transversion (purine -> pyrimidine)
   —– AP site so causes steric problems
4. insertion
5. deletion

Question 4

what causes spontaneous mutations?

Answer 4

just randomly happens
- they usually happen during DNA replication or after

Question 5

4 induced mutations

Answer 5

1. base analogs (molecules that mimic DNA bases)
2. DNA-modifying agents (chem changes to DNA bases)
3. intercalating agents (distortion in the DNA strand)
   —–ex: thymine dimers
4. DNA lesions (gap in the strand due to the glycosidic bond being broken)
   – AP site (so a prob just like in the transversion mutation)

Question 6

what causes induced mutations?

Answer 6

radiation, chemicals, infectious agents