Bacterial genetics notes:
1. what are the characteristics of a eukaryotes?
- membrane bound organelles
- defined nucleus
- diploid genome
2. what are the characteristics of a prokaryote?
- no membrane bound organelles
- no nucleus
- peptidoglycan cell wall
- gram -ve have LPS in outer membranes
- bacterial specific structures eg pilli, flagella and porins
3. describe the bacterial genome
- haploid
- circular chromosome
- double stranded DNA
- some episomal elements = plasmids
- transferable DNA
- have viruses (bacteriophage)
4. what is a plasmid?
- independent small DNA molecule which replicate independently
5. what enables bacteria to have transferable DNA?
- F plasmids
6. how do bacteriophages replicate?
- target surface structures of bacteria in order to infect nucleic acid = bacteria produces
more virus
7. describe the characteristics of bacterial chromosomes
- haploid = circular DNA
- longer than the prokaryote = tightly packed into the cell
- organised into a DNA protein complex = nucleoid
8. describe the characteristics of bacterial plasmids
- copy number can range per cell
- has parturition genes so when bacteria divide both cells gain plasmid
- not all bacteria have plasmids
- can transfer between related bacteria to carry a range of properties
9. how do methylation patterns of bacterial DNA differ?
- methylation patterns of DNA different between kingdoms
20. what bacterial DNA nucleotides are un-methylated ?
- bacterial DNA CpG dinucleotides
21. what is a CpG motif?
- where a cytosine triphosphate deoxynucleotide ("C") is followed by a guanine
triphosphate deoxynucleotide ("G").
, 22. what activates TLR-9 receptors?
- unmethylated CpG motifs
23. why does the activation of TLR-9 receptors via unmethylated CpG motif cause
inflammation?
- because unmethylated CpG motifs are recognised as non-self
24. what is a nucleoid ?
- tightly packed genome
25. what supercoils the nucleoid?
- DNA gyrase
26. what is present within the nucleoid ?
- genome
- DNA binding proteins
- RNA polymerase
- RNA
- bound regulatory proteins
27. what does supercoiling of DNA involve?
- breaking the strand and passing the loop through the break and reforming the break
- repeated lots of times so DNA becomes coiled on itself
28. what do fluoroquinolone antibiotics target?
- DNA gyrase = therefore stops supercoiling of DNA
29. why do bacterial genomes vary in size?
- some bacteria have more genes than others
- genes make up what a bacteria can do
- some have plasmids
30. how does transcription and translation of prokaryotic DNA differ from eukaryotic DNA?
- prokaryotes do not have introns = can be transcribed straight to mRNA
- translation of mRNA is via ribosomes
31. how can key point genes of a bacterial chromosome be classified ?
- by function = core biochemistry, regulatory, replication, virulence, transport
32. describe the characteristics of plasmids
- typically circular (few linear)
- double stranded DNA
- separate from the chromosomal DNA
- some have suicide gene to ensure maintenance
- some are transmissible by conjugation
33. how do plasmids vary between bacteria?
- variable size
- variable copy number
- can have replication and parturition genes, transfer genes, pilus gene, undefined genes
ect
34. what are replication and parturition genes?
1. what are the characteristics of a eukaryotes?
- membrane bound organelles
- defined nucleus
- diploid genome
2. what are the characteristics of a prokaryote?
- no membrane bound organelles
- no nucleus
- peptidoglycan cell wall
- gram -ve have LPS in outer membranes
- bacterial specific structures eg pilli, flagella and porins
3. describe the bacterial genome
- haploid
- circular chromosome
- double stranded DNA
- some episomal elements = plasmids
- transferable DNA
- have viruses (bacteriophage)
4. what is a plasmid?
- independent small DNA molecule which replicate independently
5. what enables bacteria to have transferable DNA?
- F plasmids
6. how do bacteriophages replicate?
- target surface structures of bacteria in order to infect nucleic acid = bacteria produces
more virus
7. describe the characteristics of bacterial chromosomes
- haploid = circular DNA
- longer than the prokaryote = tightly packed into the cell
- organised into a DNA protein complex = nucleoid
8. describe the characteristics of bacterial plasmids
- copy number can range per cell
- has parturition genes so when bacteria divide both cells gain plasmid
- not all bacteria have plasmids
- can transfer between related bacteria to carry a range of properties
9. how do methylation patterns of bacterial DNA differ?
- methylation patterns of DNA different between kingdoms
20. what bacterial DNA nucleotides are un-methylated ?
- bacterial DNA CpG dinucleotides
21. what is a CpG motif?
- where a cytosine triphosphate deoxynucleotide ("C") is followed by a guanine
triphosphate deoxynucleotide ("G").
, 22. what activates TLR-9 receptors?
- unmethylated CpG motifs
23. why does the activation of TLR-9 receptors via unmethylated CpG motif cause
inflammation?
- because unmethylated CpG motifs are recognised as non-self
24. what is a nucleoid ?
- tightly packed genome
25. what supercoils the nucleoid?
- DNA gyrase
26. what is present within the nucleoid ?
- genome
- DNA binding proteins
- RNA polymerase
- RNA
- bound regulatory proteins
27. what does supercoiling of DNA involve?
- breaking the strand and passing the loop through the break and reforming the break
- repeated lots of times so DNA becomes coiled on itself
28. what do fluoroquinolone antibiotics target?
- DNA gyrase = therefore stops supercoiling of DNA
29. why do bacterial genomes vary in size?
- some bacteria have more genes than others
- genes make up what a bacteria can do
- some have plasmids
30. how does transcription and translation of prokaryotic DNA differ from eukaryotic DNA?
- prokaryotes do not have introns = can be transcribed straight to mRNA
- translation of mRNA is via ribosomes
31. how can key point genes of a bacterial chromosome be classified ?
- by function = core biochemistry, regulatory, replication, virulence, transport
32. describe the characteristics of plasmids
- typically circular (few linear)
- double stranded DNA
- separate from the chromosomal DNA
- some have suicide gene to ensure maintenance
- some are transmissible by conjugation
33. how do plasmids vary between bacteria?
- variable size
- variable copy number
- can have replication and parturition genes, transfer genes, pilus gene, undefined genes
ect
34. what are replication and parturition genes?
