Structure Movement Transport Mutation & Gene transfer Flashcards
Cellwall?
Prevent lysis and rigidity
Plasmids?
Extrachromosomal DNA. Conjugation, resistance, digestion and toxins.
Periplasma?
Between outer cytoplasmic membrane and inner surface of LPS.
Capsules?
Attachment and prevent dehydration
Fimbrae?
Stick to surfaces. Pericolus and biofilms
Biofilms?
Growth mats. Prevent chemicals, barrier for grazing, washed to new habitats.
Flaggelum?
Motility and adhesion
Kinds of flaggella?
Polar - @ 1 end - amphitocus @ Both ends - lophotricous.
Petrichous - Around the cells surface
Movement?
Chemotaxis and phototaxis by []-gradient.
Petrichous - Tumbles and random runs
Polar - Runs by start/stop and reverse the motion
Proton motife force?
Active proton symport.
Translocation through a MOT complex and ~1200 H+ gives rotation to the whole basal body.
Speed = flowrate of H+
Passive transport?
Diffusion
Fascilitated diffusion
Osmosis
Active transport? In Gram+ and Gram-?
ATP Simple or Group Symport/Antiport Ex. ABC-system Gram negative - periplasma Gram positive - transmembrane protiens
Pili?
Receptors for adhesion, conjugation and motility.
F = Fertility
P = Adherence
Structure & staining Gram+ ?
Plasmamembrane
Peptidoglycan
Staining - Purple/violett
Structure & Staining Gram- ?
Less peptiodoglycan
LPS
Staining - Pink
LPS?
Core specific
O - specific
Lipid A
Braun lipidlayer - connects LPS to peptidoglycan
Rotor and strator?
Rings
Basal body
MOT proteins
In gram- ?
L-ring
P-ring
MS/C-ring
Rings In gram+ ?
MS/C-rings
Endospores?
Survival structure
Resistant to heat, chemicals and radiation
Endosporulation?
Activation -> Germination -> Outgrowth
Vegetative cell Endospore
Exosporium?
DPA + Ca2+
Binds to H2O and stabiliezes DNA
DNA transfer?
Rolling circle replication
Operon?
Polycistronic mRNA
Genes encoding proteins in the same pathway, clustered and transcribed to form 1 mRNA for all.
Virulence factors?
Assists in infections through increasing adhesion
Bacteriocins?
Inhibit or kills related bacterial species
Transposable elements?
Seq. inserted to DNA but can move from one site to another.
Transcription?
Sigma 70 Pribnowbox RNA Pol GC-rich sequence RNA stemloop structure
Translation?
Charged tRNA
mRNA recognized by 30S and 50S –> 70S
Initiation and elongation factors
Polysome?
mRNA translated continously
Stopcodon with release factors
No factors –> tmRNA
Affecting transcription?
Repression
Induction
Net synthesis is unaffected
Repression?
Corepressor
Adding AA to repress the synthesis
Induction?
Inducer
Adding Substrate to induce the synthesis
Catabolite repression?
Mechanism for global control of carbon sources
The glucose effect
Prevents expression of other catabolic operons as long as glucose is present.
Diauxic growth?
2 exp. phases as 2 sources of carbon are present.
Ex. First glucose –> then lactose –> increasing expression of the lac operon.
Mutations?
Permanent* change in DNA and the driving force of evolution.
In nucleotide - mutant
In phenotype - mutant phenotype
Genotype / Phenotype?
Genotype - hisC1 - hisC2 - hisC3
Phenotype - HIS+ or HIS-
Point?
1 nucleotide position is altered
Silent?
3rd base is altered
Missense?
1st or 2nd base is altered
Non-sense?
Stopcodon
Transitions?
Purine –> Pyrimidine
Transversion?
Purine –> Purine
Indels?
1 Base –> Change in primary seq
2 Bases –> Frameshift
3 Bases –> Addition / Deletion of an AA
Mutations Reversions?
*
Same-site –> Restored acitivity
True –> Restored seq
2nd site –> @ same gene that restores function
Suppressor mutations?
Compensate the effect of ori. mutation
Horizontal gene transfer?
Transduction
Conjugation
Transformation
Transduction?
Bacteriophages
Region of DNA recombinates and integrates to the genome
GTA’s –> Defective bacteriophages used to disperese genes to the local environment = geneflow in nature
Transformation?
A competent cell takes up free DNA
Involves many components: DNA-binding proteins Autolysine Nucleases Electropolatine RecA
From Griffiths experiment where a virulence factor - capsule - was found in some bacteria but not all. Capsule = Increased virulence
Conjugation?
F-pili F-plasmid is integrated to the host Non-integrated - F+ Integrated - Hfr Chromosome + plasmid - F- In short - form a single molecule of DNA and require the tra-operon.
