chapter 10

Question 1

a chemical that kills or stops the growth of a microorganism

Answer 1

antibiotic or antimicrobial agent

Question 2

the antibiotic is produced by and organism and then engineered in a lab to be more effective, longer lasting or easier to administer

Answer 2

semisynthetic antibiotics

Question 3

antibiotics that are completely made in a lab

Answer 3

synthetic antibiotics

Question 4

the antibiotic is more toxic to the pathogen than our cells

Answer 4

selective toxicity

Question 5

who proposed the idea of chemotherapy, the use of chemicals that would selectively kill pathogens with little to no harm to the patient

Answer 5

paul ehrlich

Question 6

chemicals that would bind to the receptors of bacteria while ignoring host cells that did not possess the same receptors

Answer 6

magic bullets

Question 7

who discovered the antibacterial action of penicillin released from pencicillium mold which created a zone where bacteria could not grow

Answer 7

alexander fleming

Question 8

discovered the first antimicrobial agent affective in treating a wide range of bacterial infections (broad spectrum antibiotic)

Answer 8

gerhard domagk

Question 9

stops the synthesis of folic acid which is required for the synthesis of RNA in DNA in bacteria only

Answer 9

sulfanilamide

Question 10

discovered that microbes are an invaluable source of producing antimicrobial agents

Answer 10

selman waksman

Question 11

how does streptomyocin work

Answer 11

binds to small subunit of the ribosome blocking protein synthesis in bacteria

Question 12

what is the antimicrobial strategy to stop cell wall synthesis

Answer 12

stop enzymes from making NAM-NAM cross bridges

Question 13

a class of drugs that contain a beta-lactam ring that irreversibly binds to enzymes that produce NAM-NAM cross bridges

Answer 13

beta-lactams

Question 14

EXAM QUESTION #1

Answer 14

Bacteria cells need to produce peptidoglycan strands and add them to their cell wall to grow and divide. They use an enzyme to make NAM-NAM tetrapeptide cross bridges to attach the new peptidoglycan strands to the cell wall. Beta-lactam drugs irreversibly bind to the enzyme that makes tetra cross bridges which weakens cells wall which will then result in death by osmotic pressure

Question 15

block the formation of specific alanine crossbridges which weakens the cell wall

Answer 15

vancomyocin and cycloserine

Question 16

blocks transport of NAG and NAM from cytoplasm; if you cannot get NAG and NAM out of the cytoplasm you cannot build the cell wall

Answer 16

bacitracin

Question 17

the only drugs that disrupt mycolic acid formation in mycobacterium

Answer 17

isoniazad and ethambutol

Question 18

examples of drugs that inhibit protein synthesis

Answer 18

tetracyclin, chloramphenicol and streptomycin

Question 19

which drug binds to the ribosome and blocks the tRNA from being able to dock and deliver a new amino acid - the synthesis of the protein is prevented

Answer 19

tetracycline

Question 20

a critical support molecule in the plasma membrane that fungi contain, lipid that maintains the structural integrity of the cell membrane of fungal cells

Answer 20

ergosterol

Question 21

class of fungicides that bind to ergosterol

Answer 21

polyenes

Question 22

a polyene that binds to ergosterol and drills a hole through it

Answer 22

amphotericin B

Question 23

drugs that inhibit the cell’s ability to make ergosterol

Answer 23

azoles and allylamines

Question 24

what happens without ergosterol

Answer 24

a fungal cell’s cytoplasmic membrane does not remain intact -> cell death

Question 25

why are azoles and allylamines harmless to humans

Answer 25

they target a chemical pathway to produce ergosterol that does not exist in our bodies

Question 26

binds to DNA and effectively blocks DNA replication and RNA transcription not only in bacteria but in their host cells - affected because bacteria and cancer cells divide much faster that normal cells in our body used to treat bacterial infections and in chemotherapy

Answer 26

actinomycin

Question 27

inhibit the activity of an enzyme called DNA gyrase stopping DNA replication

Answer 27

quinolones

Question 28

an enzyme that exists only in prokaryotes and is necessary for the correct coiling and uncoiling of DNA that is replication

Answer 28

DNA gyrase

Question 29

binds to RNA polymerase a lot more in prokaryotes than eukaryotes which stops transcription in bacteria - they then cannot make mRNA and bacteria cannot make proteins without mRNA

Answer 29

rifampin

Question 30

molecules that are structurally very similar to the normal nucleotides

Answer 30

nucleotide analogs

Question 31

the sum of all reactions that occur in an organism and provide energy for sustaining living processes

Answer 31

metabolism

Question 32

affect metabolic process that are unique to pathogens and do not occur in humans

Answer 32

antimetabolic agents

Question 33

prokaryotes convert PABA into

Answer 33

folic acid

Question 34

acts as a coenzyme that is required to synthesize nucleotides

Answer 34

folic acid

Question 35

act as structural analog of PABA and bind to an enzyme involved in its conversion to folic acid

Answer 35

sulfonamides or sulfa drugs

Question 36

what is the strategy to inhibit virus attachment to a cell

Answer 36

use a protein or carbohydrate that blocks the chemical interaction between a virus and a host cell

Question 37

class of drugs being researched that prevent virus from attaching to a host cell which prevents injection of viral DNA

Answer 37

attachment antagonists

Question 38

antiviral drugs that prevent dissociation of the protein coat which is necessary for a virus to inject into a host cell

Answer 38

dissociation antagonists

Question 39

prevent the release of newly formed viruses from host cells

Answer 39

transition antagonists

Question 40

characteristic of ideal antibiotic

Answer 40

- inexpensive - readily available - chemically stable - easily administered - non-toxic - selectively toxic against a wide range of pathogens

Question 41

effective against few organisms

Answer 41

narrow spectrum

Question 42

effective against many organisms

Answer 42

broad spectrum

Question 43

if normal flora is killed what happens

Answer 43

there is additional space and resources for pathogens and bacteria to colonize which leads to secondary infections

Question 44

the bacteria that are part of our normal flora occupy space and use resources preventing bacteria from gaining access to our body or colonize

Answer 44

microbial antagonism

Question 45

number of different pathogens a drug acts against

Answer 45

spectrum of action

Question 46

what is the diffusion of susceptibility test also known as

Answer 46

kirby-bauer test

Question 47

clear area where the pathogen did not grow

Answer 47

zone of inhibition

Question 48

how does the molecular wight of the antibiotic affect the size of the zone of inhibition

Answer 48

light weight diffuses a larger distance into agar where heavy weight diffuses a small distance from disc

Question 49

the smallest amount of an antibiotic that will stop growth and reproduction of a pathogen

Answer 49

minimum inhibitory concentration

Question 50

the mic is often determined by a

Answer 50

broth dilution test

Question 51

drug used for external infection

Answer 51

topical application

Question 52

requires no needles and is self-administered

Answer 52

oral route

Question 53

administration delivers drug via needle into muscle

Answer 53

intramuscular

Question 54

administration delivers drug directly to the bloodstream

Answer 54

intravenous

Question 55

resistance by bacteria aquired in two ways

Answer 55

1. new mutations of chromosomal genes 2. acquisition of resistance plasmids via conjugation, transduction, and translation

Question 56

resistant and persistors are in the majority or minority

Answer 56

minority

Question 57

what is in the majority

Answer 57

regular bacteria

Question 58

cells in a population that resist the effects of antimicrobial drugs despite being genetically identical to susceptible cells

Answer 58

persister cells

Question 59

why are persister cells believed to be tolerant

Answer 59

metabolically inactive and grow slowly