(1/15/15) Effects of Antibiotics on Life Cycle of Bacteria (Bailey)

Question 1

type of antibiotic that actually kills the bacteria

Answer 1

bactericidal

Question 2

type of antibiotic that prevents bacteria from replicating but does not kill it

Answer 2

bacteriostatic

Question 3

_______ antibiotics occur more rapidly than ______ ones

Answer 3

• bactericidal

- bacteriostatic

Question 4

tetracycline is a ______ antibiotic

Answer 4

bacteriostatic

Question 5

penicillin is a _____ antibiotic

Answer 5

bactericidal

Question 6

what are the 4 requirements of an ideal antibiotic

Answer 6

1. broad spectrum of activity
2. would not induce resistance
3. high therapeutic index
4. selective toxicity

Question 7

is a high or low therapeutic index better for the host?

Answer 7

high (bc it means that you can have a very small, nonleathal dose of antibiotic and it will not kill the host but will kill the bacteria)

Question 8

to achieve selective toxicity, a microbe must have _____ cell walls and enzyme replication as well as ribosome structure

Answer 8

unique

Question 9

what are the five ways in which an antibiotic can inhibit bacteria

Answer 9

1. inhibition of cell wall synthesis
2. disruption of cell membrane function
3. inhibition of protein synthesis
4. action as antimetabolites
5. inhibition of nucleic acid synthesis

Question 10

all penicillins have _____ _____

Answer 10

beta-lactane rings

Question 11

how does penicillin disrupt cell wall synthesis?

Answer 11

it cause competition for the substrate and also becomes toxic to bacteria in its cleaved form

Question 12

______ ____ _____ disrupts cell membrane function by binding to phospholipids

Answer 12

polymyxin B sulfate

Question 13

antibiotic that prevents formation of initiation complex in blockage of the ribosome cycle

Answer 13

linezolid

Question 14

antibiotic that blocks tRNA from attaching by binding to 30s subunit in the blockage of the ribosome cycle

Answer 14

tetracycline

Question 15

antibiotic that blocks elongation but not RNA binding in the blockage of the ribosome cycle

Answer 15

aminoglycosides

Question 16

antibiotic that binds to 50s to inhibit chain elongation causing the ribosome to dissociate from RNA in the blockage of the ribosome cycle

Answer 16

macrolides chloramphenicol

Question 17

what is the only antibiotic that can inhibit DNA replication?

Answer 17

metronidazole

Question 18

sulfa-drugs are ______

Answer 18

bacteriostatic

Question 19

because of the _____ _____ exerted by antibiotics, bacteria have become resistant within one human genome

Answer 19

selective pressure

Question 20

what are the three steps in the action of antibiotics?

Answer 20

1. drug penetrates the envelope
2. transports into the cell
3. drug binds to target

Question 21

at which step does resistance to drugs occur?

Answer 21

at all three

Question 22

what are the three mechanisms of drug resistance?

Answer 22

1. synthesis of enzymes that inactivate the drug
2. prevention of access to the target site
3. modification of the target site

Question 23

many antibiotics enter the cell through _____

Answer 23

porins

Question 24

some bacteria develop _____ pumps to pump the antibiotics out of them

Answer 24

efflux (all bacteria have these, just a matter of how strong they are)

Question 25

what are the three ways that antibiotic resistance spreads?

Answer 25

1. chromosome associated resistance
2. plasmid mediated resistance
3. rapid spread of resistance

Question 26

what are the three ways to combat an antibiotic resistant pathogen?

Answer 26

1. synergism
2. antagonism
3. indifference

Question 27

failure to eliminate the pathogen could likely increase the likelihood of _______

Answer 27

superinfection

Question 28

what are antibiotics not effective against?

Answer 28

viruses