Topic 6: prokaryotes bacteria + archaea Flashcards
Give 3 domains of life
1) Bacteria
2) Archaea
3) Eukarya
What do bacteria + archaea consist of?
Unicellular prokaryotes
What do eukarya consist of?
- Protists
- Fungi
- Plants
- Animals
Give the prokaryotic/eukaryotic micro/macro-organisms
MICRO-ORGANISMS:
- Prokaryotic = archaea/bacteria
- Eukaryotic = protists/fungi
MACRO-ORGANISMS:
- Prokaryotic = not existing
- Eukaryotic = animal/plants
What did Pasteur do?
- Discovered role of pathogenic bacteria in transmitting infectious disease
What did Koch do?
- Discovered Vibrio cholerae = pathogen causing cholera
What did Alexander Fleming do?
- Discovered penicillin
Give examples of viral pandemics
- HIV/AIDS
- Flu pandemics
- Asian flu
Give examples of bacterial pandemics
- Cholera
- Black death
What bacterium caused Black death?
Yersinia pestis
Describe the 1st antibiotic
- Discovered accidentally = mold growing killed Staphylococcus aureus
- 12 years later purified + isolated penicillin drug
Describe the properties of prokaryotes
- Unicellular microorganism
- 1 prokaryotic cell
- Replicate faster than eukaryotes
- Smaller in size than eukaryotic cell
- Size = 1-10 µm
- Variable morphology
- Domains = bacteria/archaea
- Can thrive in extreme conditions
2 types of bacteria
1) Eubacteria
2) Cyanobacteria
Describe eubacteria
- Pathogenic bacteria = causing disease
Describe cyanobacteria
- Non-pathogenic
- Have chlorophyll = photosynthesize = produce oxygen
- Live in lakes + oceans
- Role = nitrogen fixation
Describe archaea
- Initially named archaebacteria = morphological similarities to bacteria
- Phylogenetic analysis = revealed molecular similarities to eukaryotes
- Live in extreme conditions
3 types of archaea
1) Halophiles
2) Methanogens
3) Thermoacidophiles
Describe halophiles
- In salt lakes
Describe methanogens
- In digestive track
- Anaerobes
- Produce methane
Describe thermoacidophiles
- Acidous + sulphur-rich hot springs
- Optimum temp = 70-80° C
- Optimum pH = 2-3
How is the nomenclature of microorganisms?
- Species name = genus + characteristic property
Types of prokaryotic morphology
1) Spherical shape = cocci
- Staphyloccoci + streptococci
2) Rod shape = rods
- Bacilli + E.coli
3) Spiral shape
- C/S shape = Vibrio cholerae
- Spirila + Spirochetes
Compare prokaryotes/eukaryotes
PROKARYOTES:
- Smaller in size
- No nuclear membrane
- No membrane bound organelles
- No replicative cell cycle = bonary fission instead
- Different cell wall composition than eukaryotes
Describe the function of a cell wall
- Maintain cell shape
- Protects cell
- Prevents cell = bursting in hypotonic environmenet
- Role in cell division
