1.1 Intro Flashcards
What are the several types that microorganisms can be divided into ?
- bacteria
- archaea
- fungi
- helminths + parasites
- protozoa
- algae
Name 2 ‘not technically microorganisms but can be pathogens’
- prions
- viruses
Prokaryotes are :
1. organism cell type ?
2. lack of what ?
3. 2 examples ?
- unicellular
- membrane-bound nucleus & other specialised organelles
- bacteria and archae
Eukaryotes:
1. organism cell type ?
2. cells contain ?
3. 5 examples
- unicellular / multicellular
- nucleus, other membrane-bound organelles
- fungi, algae, protozoa, helminths, parasites
How is bacteria often named by?
Genus and species
Genus species -> S. aureus
3 main characteristics used for classification of bacteria:
- cell morphology (shape)
- staining properties
- oxygen requirement
- All bacteria can be divided into 2 groups which are ?
- what are the differences between the 2 groups due to ?
- gram negative or positive
- structure of the cell wall in the bacteria
Compare gram positive + gram negative bacteria features
1. peptidoglycan layer
2. outer membrane
3. LPS
4. staining colour
5. 2 examples of each
- = thick , - = thin
- = no , - = present
- = no, - = present
- = blue/purple , - = pink/red
- = S.aureus, Streptococci , - = E. coli, salmonella spp
Why are different antibiotics used for different infections ?
structure of peptidoglycan cell wall
Why is it important to know if the bacteria causing an infection is gram negative or gram positive ?
different antibiotics are used fot different infections due to structure of peptidoglycan cell wall
- Gram staining involves a series of …. that dye bacterial cells
- this includes … ?
- sequential steps
- crystal violet, iodine, alcohol and safranin
Why do gram positive bacteria appear purple under the microscope ?
- due to thick peptidoglycan layer in cell wall
- retain the crystal violet-iodine complex
Why do gram negative bacteria appear pink ?
they lose the stain (crystal violet-iodine complex) due to thin peptidoglycan layer in their wall and appear pink after counterstaining with safranin
Based on bacterial susceptibility patterns what does gram staining help guide with ?
antibiotic selection and treatment
3 examples of cocci (spherical) bacteria
- staphylococcus aureus
- streptococcus pneumoniae
- neisseria gonorrhoeae
3 examples of bacilli (rod shaped) bacteria
- escherichi coli
- bacillus anthracis
- pseudomonas aeruginosa
3 examples of spiral bacteria
- treponema pallidum
- campylobacter jejuni
- helicobacter pylori
aerobic bacteria microorganisms that require ?
oxygen to grow and survive
examples of aerobic bacteria (require oxygen to grow and survive)
- mycobacterium tuberculosis
- pseudomonas aeruginosa
anaerobic bacteria =
1. organisms that can survive and grow in ….
2. obtain energy through ?
- absence of oxygen or with very low oxygen levels
- fermentation or anaerobic respiration
4 examples of anaerobic bacteria ?
- clostridium botulinum
- bacteriodes fragilis
- fusobacterium spp
- prevotella spp
Environment that faculative anaerobic can grow in ?
both oxygen-rich (aerobic) and oxygen-poor (anaerobic)
2 examples of faculative anaerobic bacteria
- escherichia coli
- staphylococcys aureus
Bacteria reproduce by ?
binary fission
What is binary fission as a process which does what ?
one parent cell divides to form 2 progeny cells
why are bacteria said to undergo exponential growth (logarithmic growth)?
because one cell gives rise to 2 progeny cells
what are the 4 major phases of growth cycle of bacteria ?
- lag phase
- log phase
- stationary phase
- death phase
what happens in lag phase of bacterial growth cycle ? & how long does it last ?
- vigorous metabolic activity , but cells don’t divide
- can last few minutes up to many hours
what happens in log (logarithmic) phase of bacterial growth cycle ?
rapid cell division occurs
Stationary phase occurs when….
…1…. or toxic products cause growth to …2… until the number of new cells produced ..3… the number of cells that die resulting in a …4…
- nutrient depletion
- slow
- balances
- steady state