Bacteria Flashcards
Why study bacteria?
- good genetic models
- bacterial pathogens
- biotechnology
Why do bacteria make good genetic models?
- grow very quickly
- haploid
- easy to manipulate genome
- no ethical concerns
Prokaryotes vs. Eukaryotes
Ribosomes
P - 70s
E - 80s
Prokaryotes vs. Eukaryotes
Size
P - 1-4microm
E - bigger than 5 microm
Prokaryotes vs. Eukaryotes
Mitosis
P - no mitosis
E - mitosis
Prokaryotes vs. Eukaryotes
nucleus
P - not present
E - present
Prokaryotes vs. Eukaryotes
mitochondria
P - not present
E - present
Prokaryotes vs. Eukaryotes
chloroplasts
P - not present
E sometimes present
Prokaryotes vs. Eukaryotes
ER
P - no ER
E - ER
Prokaryotes vs. Eukaryotes
Cell Wall Material
P - peptidoglycan
E - chitin or cellulose if present
Prokaryotes vs. Eukaryotes
Flagella
P - simple flagella
E - complex flagella
Bacteria Reproduction
- binary fission
- short generation times
- divide every 1-3 hours
Bacterial Cell Walls
- peptidoglycan
- cross linked
- maintains shape
- prevents bursting in hypotonic event
Bacterial Shapes
- spiral
- spherical
- rod shaped
Bacterial Movement
-flagellum / flagella
By what methods do bacteria acquire new traits?
- transformation
- transduction
- conjugation
Transformation
- uptake and incorporation of DNA from the surrounding environment
- membrane proteins transport DNA into cell
Transduction
- movement of genes between bacteria and bacteriophages
- bacteriophage takes DNA from one bacterium into another by mistake
Conjugation
- genetic material transferred between bacterial cells
- plasmid DNA moves from a donor cell to a recipient cell via the pillus
- this is horizontal transfer across a generation rather than down to the next generation
Mutualism
both symbiotic organisms benefit
Commmenalism
only one organism benefits, but it doesn’t help or harm the other
Parasitism
organism harm but does not kill the host
Pathogen
causes disease and kills the host
What are cyanobacteria?
photoautotrophs that generate oxygen
Cyanobacteria and Chloroplasts
chloroplasts likely evolved from cyanobacteria by endosymbiosis
Bioremediation
bacteria can be used to clear up pollution
Gram Positive Membrane
- cell plasma membrane
- thick layer of peptidoglycan
Gram Negative Membrane
- cell membrane
- periplasmic space
- thin layer of peptidoglycan
- outer membrane
Gram Positive Membrane
Gram Stain
- peptidoglycan traps the crystal violet
- masks dye
- appears purple
Gram Negative Membrane
Gram Stain
- crystal violet is easily washed away
- red dye is visible
- appears red
Photoautotroph
Energy Source - light
Carbon Source - CO2 or HCO3
Examples - photosynthetic prokaryotes, plants, protists
Chemoautotroph
Energy Source - inorganic chemicals
Carbon Source - CO2 or HCO3
Examples - unique to certain prokaryotes
Photoheterotroph
Energy Source - light
Carbon Source - organic compounds
Examples - unique to certain salt loving and aqueous prokaryotes
Chemoheterotroph
Energy Source - organic compounds
Carbon Source - organic compounds
Examples - many prokaryotes, animals, fungi, some plants
