1. Mutation In Bacteria
Dr.Gulve R.M

2. Mutation are Permanent, heritable DNA changes in bacterial DNA
Types of Mutation
Point mutation (base substitutions)
Missense mutation
Nonsense mutation (premature stop)
Silent mutation
Insertions/deletions
Frameshift mutation
Dramatic change in amino acids
Run-ons,
premature stops (nonsense mutation) .

3. Occurs in DNA replication (1 in 109 bp) Chemical mutagens
The Creation of Mutation (mutagenesis)
Spontaneous mutation
Occurs in DNA replication (1 in 109 bp)
Chemical mutagens
Base pair changers (nitrous acid)
Base analogues (e.g.. 5 bromouracil)
Frameshift mutagens (aflatoxin, benzpyrene)
Radiation
X rays, gamma rays break DNA, bases
UV light causes knots in DNA strand
Mutations in the genetic instructions usually changes the resultant protein with deleterious effects

4. A heritable change in the genetic material called Mutation.
Mutations may be neutral, beneficial, or harmful
Mutagen are agent that causes mutations
Spontaneous mutations are mutation occurs in the absence of a mutagenic agent

7. Base pair altering chemicals (base modifiers) deaminators like nitrous acid, nitrosoguanidine, or alkylating agents like cytoxan
Base analogues “mimic” certain bases but pair with others - E.g. 5-fluorouracil, cytarabine

8. Ionizing radiation (X rays, gamma rays, UV light) causes the formation of ions that can react with nucleotides and the deoxyribose-phosphate backbone.
Nucleotide excision repairs mutations

10. UV radiation causes thymine dimers, which block replication.
Light-repair separates thymine dimers
Sometimes the “repair job” introduces the wrong nucleotide, leading to a point mutation.