Term
| distinguishing factors of a prokaryote? |
|
Definition
no nuclear membrane
no organelles |
|
|
Term
| how can bacteria transfer virulence genes withing and between species? |
|
Definition
| plasmids (self replicating DNA) |
|
|
Term
| what propels the flagella? |
|
Definition
| Ion motive force (not a virulence factor) |
|
|
Term
| describe the flagella of monotrichous |
|
Definition
|
|
Term
| describe the flagella of amphitrichous |
|
Definition
|
|
Term
| describe the flagella of lophotrichous |
|
Definition
| a cluster of flagella at one pole |
|
|
Term
| describe the flagella of peritrichous |
|
Definition
| glagella encircling the cell |
|
|
Term
| which direction does a flagellum grow? |
|
Definition
| from the tip, not the base |
|
|
Term
|
Definition
| a bacteria swimming up a concentration gradient. VIRULENCE FACTOR |
|
|
Term
| what type of bacteria most often has pili and fimbriae? |
|
Definition
|
|
Term
| what is the function of 'F' or 'sex' pili? |
|
Definition
To transfer DNA to others cells (conjunction). It's longer and thicker than other types.
Also, its a receptor for bacteriophages which are viruses that can infect bacteria |
|
|
Term
| are pili and fimbrae virulence factors of bacteria? |
|
Definition
|
|
Term
| what is the difference between a capsule and glycocalyx? |
|
Definition
| capsules are uniform and condensed around the cell while glycocalyx forms a loose meshwork of fibrils that extend outward from the cell |
|
|
Term
| Why are capsules a virulence factor? |
|
Definition
| resist changes in osmolarity (high salt/low salt) and protect against phagocytosis |
|
|
Term
| why is E. coli able to be engulfed while streptococcus isn't? |
|
Definition
|
|
Term
| what is the function of the cell wall? |
|
Definition
| provides shape and resistance to osmotic pressure differences between the environment and cytoplasm |
|
|
Term
| why must Mollicutes live in a resticted envirment where the osmlarity doesn't change? |
|
Definition
They don't have a cell wall
(not affect by penicullin bc no cell wall) |
|
|
Term
| what color do gram-positive cells stain? |
|
Definition
|
|
Term
| what is the difference between gram-positive and negative bacteria? |
|
Definition
The cell wall
postive have a thick outer wall with no lipids while gram-negative have a thin wall and outer membrane |
|
|
Term
| alcohol/acetone washes away anything attached to the outer membrane of what type of bacteria? |
|
Definition
|
|
Term
| what is the protcol for a gram stain? |
|
Definition
1. Heat fix
2. Cyrstal violet
3. Iodine
4. De-colrize
5. Counter stain |
|
|
Term
| what's the function of the cell envelope? |
|
Definition
| protect cell against environmental changes (osmotic pressure) |
|
|
Term
| what makes of the cell wall? |
|
Definition
|
|
Term
| what is the difference between gram negative and postive bacteria regarding their peptidogylcan layer? |
|
Definition
Negative only has 1 layer (but it's got a outer membrane)
postive has 15-20 layers |
|
|
Term
| why are gram-postive cells more resistant to dry locations? |
|
Definition
| thicker peptidoglycan layer, but this also makes them more suseptible to penicillin |
|
|
Term
| what amino acid of found in the tetrapeptides of gram-negative bacteria? |
|
Definition
|
|
Term
| what amino acid of found in the tetrapeptides (cross linking) of gram-positive bacteria? |
|
Definition
lysine
(except staphlococcus aerues has glycine) |
|
|
Term
| what type of bacteria would have techoic acid in their cell wall? and whats it's function? |
|
Definition
gram-positive bacteria
techoic acid is negatively charged so it attracts Mg2+ Ca2+ and can bind to protons which lowers the walls pH and decreases rate of degredation by autolysins |
|
|
Term
| what bacteria type has lipoproteins? |
|
Definition
|
|
Term
| why is the outer membrane of gram-negative bacteria more permeable to small molecules than the cytoplasmic membrane? |
|
Definition
| the outer membrane has porins |
|
|
Term
| which layer of gram-negative bacteria is more permeable to hydrophobic (nonpolar) and amphipathic molecules? |
|
Definition
| the cytoplasmic membrane is more permeable |
|
|
Term
| where are lipopolysaccharides found? |
|
Definition
| the outer layer of the outer membrane of gram-negative bacteria |
|
|
Term
| what is clinically important about LPS? |
|
Definition
| its acts as a endotoxin and VIRULENCE factor |
|
|
Term
| whats the function of O-antigen found in LPS? |
|
Definition
| VIRULENCE factor for escapting phagocytosis |
|
|
Term
| why can't hydrophobic molecules cross the outer membrane of gram negative bacteria? |
|
Definition
| LPS molecules are - and attract divalent cations (Mg2+ and Ca2+) |
|
|
Term
| what is the toxic protion of LPS? |
|
Definition
Lipid A
(LPS molecule introduced into animal cause fever and even death) |
|
|
Term
| where can you find lysozyme? |
|
Definition
|
|
Term
| how does penicillin inhibit cell wall synthesis? |
|
Definition
| it forms an inactive complex with transpeptidase so cross-bridges can't from |
|
|
Term
|
Definition
| produced from Bacillus or Clostridum and are resistant to extreme heat. |
|
|
Term
| what's the function of calcium dipicolinate in an endospore? |
|
Definition
|
|
Term
| define facultative aerobes |
|
Definition
| can live with or without oxygen, derive ATP aerobically or anaerobically |
|
|
Term
| define obligate anaerobes |
|
Definition
| require oxygen, derive ATP from proton motive force from electron transport chain with oxygen as terminal electron receptor |
|
|
Term
|
Definition
| can't use oxygen as energy source, derive energy from fermentation |
|
|
Term
| what is anaerobic respiration? |
|
Definition
| when the electron transport uses fumarate or nitrate instead of oxygen and the final electron acceptor (still generates more energy than fermentation) |
|
|
Term
| why is it important to re-oxidize NADPH at the end of fermentation? |
|
Definition
| if NADPH builds up in inhibits glycolysis leading to decreased ATP synethsis |
|
|
Term
| what limits the exponential growth of bacteria? |
|
Definition
| lack of nutrients and energy |
|
|
Term
| what are the 4 stages of bacterial growth? |
|
Definition
1. lag phase
2. exponential phase
3. stationary phase
4. death phase |
|
|
Term
| what happens during the lag phase of bacterial growth? |
|
Definition
| cell in increasing in size and synsthesizing DNA and RNA but not dividing |
|
|
Term
| what is the formula for cell number? |
|
Definition
| cell number = 2^n (n equels number of generations) |
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