bacterial genetics Flashcards
list qualities of the bacterial genome
- haploid
- circular chromosome
- dsDNA
- some episomal elements (plasmids)
- transferable DNA
- they have viruses
are DNA CpG dinucleotides methylated
no - unmethylated
what is a plasmid
- typically circular (few linear)
- dsDNA
- serparate from the chromosomal DNA
- some have a suicide gene to ensure maintenance
- some are transmissible by conjugation
- variable in sizes and copy number
how do bacteria vary their genome to evolve
- mutation of genes
- transfer of genes
- rearrange their DNA
- delete genes
- new genes inserted
what effects can mutations have on bacteria
- none
- be lethal
- alter fucntion/properties
outline the process of transcription and translation and postranslational events of proteins in bacteria
transcription = DNA –> RNA
translation = RNA –> proteins
through which methods does introduction of new DNA into and between bacteria occur
- transformation
- conjugation
- transduction recombination
DNA already in the bacteria move about via which methods
- transposition
- recombination
what is transformation
- the uptake of naked DNA
- DNA contacts the bacteria and is taken up
- some bacterial are naturally competent and can take up DNA without treatment which others require lab assistance
- once naked DNA is take into cell there are 2 options: degredation by nucleases or recombination into the genome
what is conjugation
- the transfer of genetic material between bacteria through direct cell-to-cell contact
- conjugation is horizontal gene transfer
- it if the transfer of genetic information from a donor cell to a recipient
- for conjugation the donor must host a conjugative or mobilisable genetic element (plasmid or transposon)
- most conjugative plasmids have systems ensuring that the recipient cell does not already contain a similar element
what is the clinical relevence of conjugation
the transfer of plasmids can move whole blocks of properties
- antibiotic resistance
- toxins
- virulence properties
what is transduction
injection of genome into bacteria by bacteriophage
explain the process of generalised transduction by lytic bacteriophage
- attachment
- infection/injection of nucleic acid
- lag phase as things replicate
- lysis
outline the process of specialised transduction
- lysogen formed
- bacterial replication with integrated phase
- induction
- transducrion. infection with a phage with bacterial DNA, integration of new DNA
what is homologous recombination
where 2 DNA sequences are the same they can intercalate their strands. during replication these can get spliced
