Microbiology: Nature of Infection Flashcards
describe how DNA is packaged in eukaryotic cells
- linear chromosomes
- histones
- introns/exons
describe how DNA is packaged in prokaryotic cells
- single circular chromosome
- gene structure
describe how DNA is replicated in eukaryotes
cell cycle
describe how DNA is replicated in prokaryotes
- co-transcription/translation
- rapid cell cycle
describe the cell wall of eukaryotes
no/flexible
describe the cell wall of prokaryotes
rigid
describe the nucleoid of prokaryotes
- contains DNA and proteins
- no nuclear membrane
- DNA replication via DNA dependant RNA polymerase
- co-ordinated transcription/translation
- single circular chromosome, plasmids are extra ones
- primitive DNA segregation machinery
how do prokaryotes generate energy
through an electron transport chain located on the cell membrane
what are peptidoglycans
rigid layer/barrier of repeated polysaccharide structures
what is a gram +ve cell wall
one with a thick multi-layer PG
what is a gram -ve cell wall
one with a thin PG layer
what happens when a bacterial cell wall is disrupted
become liable to ‘bursting’
what are lipopolysaccharides
glycolipids with a polysaccharide core
where are lipopolysaccharides and whas is their role
- gm-ve outer cell membranes only, covers almost entire surface making it assymetrical
- structural, antigen/bacterial toxin
flagellin
protein unit, multi-stranded filament with core
what is a gram +ve flagellin
non-flagella fiprotein appendages
what is a grame -ve flagellin
no motor, pilin repeated protein unit
what is the function of fimbriae
adherence and sex
what is the function of a bacterial pili
attachment and biofilm formation
describe prokaryotic protein synthesis
gene -> mRNA -> ribosome -> tRNA -> protein ->1/2/3* structure -> export/assembly/processing
what affects prokaryotic
- plasma membrane
- cell membrane
- outer membrane and LPS
- chromosome
- ribosome
- pili, fimbirae. flagella
- sonification and ethanol
- penicillin and glycoproteins
- antibiotic uptake and inflammation
- gyrases antibiotic target
- protein synthesis inhibitors
- attachment, motility, invasion, sex, pathology
what do prokaryotes need for growth
- food (O, N, H, N), trace elements, vitamins
what are prokaryotes living at - low - high - body temp temperatures called at
- pycrophiles
- thermophiles
- mesophiles
what do pH human commensal bacteria live at
pH6.8-7.2
at what NaCl % do human commensals live at
0.85%
what is happening during
- lag phase
- growth phase
- staitonery phase
- death phase
- acclimation
- quick division
- metabolite runs out
- population decreases
