Chapter 7: Bacterial Genetics Flashcards
Genome
Complete set of genetic information.
DNA Replication
- prior to cell division
- produces two complete copies of DNA
- Each daughter cell receives one copy
- In bacteria, replication is slower than generation time.
Origin of replication
Proteins recognize and bind to a specific site on the DNA and form a protein complex
Biodirectional Replication
- 2 replication forks
- Ultimately meet at a terminating site when process is complete
Semiconservative Replication
DNA contains one original strand and one newly synthesized strand.
Semicontinuous Replication
- DNA is synthesized only in the 5’-3’ direction.
- Leading strand is synthesized continuously and lagging strand is synthesized as short Okazaki fragments.
DNA Polymerase
- Synthesizes from 5’->3’
- DNA template strand is needed
- A primer with 3’ OH
Replisomes
- Complex of several enzymes and proteins that coordinate replication.
- Works like an “assembly line”
DNA Gyrase
An enzyme that relieves strain while double stranded DNA is being unwound by helicase.
RNA Polymerase
- Synthesizes in 5’->3’
- DNA template strand is needed
- initiates without a primer.
Promoter
- Upstream DNA sequence where RNA polymerase binds
- Orientation determines direction of transcription and template strand.
Terminator
Where transcription is signaled to end.
Sigma factor
- Part of RNA polymerase hat recognizes and binds the promoter.
- Important for gene regulation
Processes of Gene Expression
- Transcription
2. Translation
Quorum sensing
How bacteria sense or talk to each other. Chemical signaling.
Ex: biofilms, bioluminescence, virulence.
