Term
| How do we traditionally classify bacteria? |
|
Definition
- their shape, gram reaction, need for oxygen
- metabolic systems |
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|
Term
| What supplemental characteristics do we also often note about bacteria (and use to classify) |
|
Definition
| - Nucleic acid sequence (especially ribsosomal encoding genes) |
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Term
| Differentiate between aerobe, anaerobe and facultative anaerobe |
|
Definition
- Aerobe: grows in air only
- Anaerobe: grows without oxygen only
- Facultative anaerobe: grows in air, and can grow without oxygen |
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Term
| What are the morphological characteristics we can use to classify bacteria? |
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Definition
| If they are cocci (spherical) vs bacilli (rods) |
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Term
| Streptococci appear in ___ or ___, whereas staphylococci appear as ___. |
|
Definition
strep = pairs or chains
staph = cluster |
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Term
| What do coccobacilli look like? |
|
Definition
| they are very short rods that can sometimes look like cocci! |
|
|
Term
| What's an example of a bacteria that has a curved rod shape? |
|
Definition
|
|
Term
|
Definition
| spiral rods such as syphilis and lyme |
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|
Term
| What kind of appendages can bacteria have? |
|
Definition
- Flagella
- Fimbriae
- Pili |
|
|
Term
| What are flagella and what do they do? |
|
Definition
- long slender protein structures
- Enable bacteria to move
- they are single and are in tufts or around cell |
|
|
Term
| What is different about flagella and fimbriae? |
|
Definition
- fimbriae are shorter, thinner filaments (they are made of protein as well)
- Enable bacteria to attach to surfaces (whereas flagella are used for motility) |
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|
Term
| Are pili more similar to flagella or fimbriae in structure? |
|
Definition
|
|
Term
| What are pili involved in? |
|
Definition
| transfer of DNA between bacteria |
|
|
Term
| Describe the bacterial chromosome. |
|
Definition
- single and circular
- not separated from cytoplasm
- lacks a nuclear membrane |
|
|
Term
| What are plasmids and what do they do? |
|
Definition
- they are small, circular pieces of DNA
- they may carry virulence factors and resistance genes |
|
|
Term
| What are conjugative plasmids? |
|
Definition
| plasmids that facilitate their own transfer (as opposed to the other guys that are dependent for transfer) |
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|
Term
Where are ribosomes in eukaryotes and prokaryotes?
Are they the same? |
|
Definition
Eukaryotes --> on the ER
Prokaryotes --> scattered throughout
NO! |
|
|
Term
| What is the structure of ribosomes? |
|
Definition
| two subunits made of RNA and protein |
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Term
| Aerobic cellular respiration: glucose becomes ___ ___ which goes through the Kreb's cycle |
|
Definition
|
|
Term
| What happens in anaerobic cellular respiration? (very basic) |
|
Definition
| Glucose becomes pyruvic acid, then through fermentation it becomes lactic acid and mixed acids |
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|
Term
| Why do facultative anaerobes go through a "hybrid pathway"? |
|
Definition
| Because they can go through the Krebs cycle or make mixed acids |
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|
Term
| What goes gram negative mean?! |
|
Definition
gram neg have:
- inner cytoplasmic membrane
- thin peptidoglycan layer
- outer membrane
- some have a capsule |
|
|
Term
| The space between the inner cytoplasmic membrane and the outer membrane is the ____ space |
|
Definition
|
|
Term
| What does gram positive mean? |
|
Definition
Gram + bacteria have:
- inner cytoplasmic membrane
- THICK peptidoglycan layer
- NO outer membrane
- some have capsules |
|
|
Term
| What is a murein monomer composed of and where is it found? |
|
Definition
- two sugars, 5 peptides, 5 glycines
- on the outside of the inner biophospholipid membrane |
|
|
Term
| ___ ___ are the building blocks for peptidoglycan |
|
Definition
|
|
Term
| What enzyme is critical to the establishment of the long murein polymers? |
|
Definition
|
|
Term
| What does vancomycin target? |
|
Definition
|
|
Term
| What does transpeptidase do? |
|
Definition
| cross links murin polymers |
|
|
Term
| What did transpeptidase used to be called before they understood its function? |
|
Definition
| penicillin binding protein |
|
|
Term
| The gram negative cell wall has 3 layers |
|
Definition
- an inner biphospholipid bilayer
- thin peptidoglycan layer
- outer membrane |
|
|
Term
| What does the gram negative cell wall do? |
|
Definition
- controls entrance and exit of substances from cell
- it has structures such as polysaccharides, integral proteins, channels, efflux pumps etc. |
|
|
Term
| What are the 4 steps to a gram stain? |
|
Definition
1. Flood slide with Crystal violet (then wash it off)
2. Flood slide with Iodine, which binds crystal violet and traps in the thick wall of gram + bacteria
3. Alcohol/Acetone washes out the stain from the gram negative bacteria (it's a decolorizer) wash with water...
4. At Safranin which stains the gram negative bacteria pink (counterstaining) |
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|
Term
|
Definition
| by binary fission (a single cell separates to form two new cells of roughly equal size) |
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|
Term
| The rate of bacterial growth is governed by... (3) |
|
Definition
1) availability of nutrients
2) temperature
3) ability to remove toxic products |
|
|
Term
| Bacterial growth is ____ when conditions are optimal |
|
Definition
|
|
Term
| What are the 4 phases of the population growth curve? |
|
Definition
1) Lag phase
2) Log phase
3) Stationary phase
4) Death phase |
|
|
Term
| What happens in the lag phase? |
|
Definition
| - adaptation to the environment and active synthesis of enzymes and other constituents |
|
|
Term
| What happens in the log phase? |
|
Definition
aka exponential phase
rapid replication! |
|
|
Term
| What happens in the stationary phase? |
|
Definition
The rate of replication equals rate of cel death
(nutrients are depleted and toxic metabolites accumulate) |
|
|
Term
| What happens in the death phase? |
|
Definition
| death rate exceeds reproduction |
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|
Term
| What can of recombinant event and molecular spread of genes can occur? (4) |
|
Definition
- transformation
- transduction
- conjugation
- transposons |
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