3 - antibiotics

Question 1

what are antibiotics

Answer 1

soluble compounds that are produced and released by microorganisms that inhibit the growth or kill other microorganisms

Question 2

what are the 3 different kinds of ways you can classify bacteria

Answer 2

aerobic vs. anaerobic
shapes
gram

Question 3

which gram stain has thicker peptidoglycan layer

Answer 3

gram positive

Question 4

which gram stain has thinner peptidoglycan layer

Answer 4

gram negative

Question 5

which gram stain has the second layer of lipopolysaccharides and lipoproteins

Answer 5

gram negative

Question 6

which kind of gram stain is most bacteria

Answer 6

gram negative

Question 7

what consists of the peptidoglycan structure

Answer 7

alternating glycan strands of NAG and NAM

Question 8

what does glycosyltransferase do

Answer 8

polymerizes individual strands (connects nag and nam) into peptidoglycan chain

Question 9

what does transpeptidase do

Answer 9

cross link the strands to contribute the overall structure of the shape

Question 10

which protein is targeted by many antibiotics (penicillin binding protein)

Answer 10

transpeptidases

Question 11

why do pathogens require an immunocompromised or injured host

Answer 11

they dont

they have big mechanisms to attack healthy people

Question 12

what is the spectrum of activity

Answer 12

narrow or broad spectrum depending on the number different bacterial species against which they exhibit useful activity

Question 13

what is bacterial sensitivity

Answer 13

assessing the ability of bacterial strain to replicate following antibiotic exposure

Question 14

what is a bactericidal antibiotic

Answer 14

death, permanent loss of replicative ability

Question 15

what is a bacteriostatic antibiotic

Answer 15

leads to temporary loss of growth and replicative ability

Question 16

what is therapeutic index

Answer 16

ratio of the minimum concentration likely to produce an adverse effect to the minimum concentration needed to produce a desired effect

Question 17

what is ability to penetrate

Answer 17

delivery of antibiotic to the site of inection is the most difficult challenge of antibiotic delivery

Question 18

what are the 4 ways to describe efficacy and potency

Answer 18

spectrum of activity
bacterial sensitivity
therapeutic index
ability to penetrate

Question 19

what are the 4 classes of antibiotics we need to know

Answer 19

cell wall inhibitors
folic acid inhibitors
DNA synthesis inhibitors
protein synthesis inhibitors

Question 20

what are the two beta lactams

Answer 20

penicillin and cephalosporin

Question 21

what kind of antibiotics are beta lactams

Answer 21

cell wall inhibitors

Question 22

why are they called beta lactams

Answer 22

they have an unusual 4 membered ring

Question 23

how do beta lactams work

Answer 23

inhibit cell wall synthesis by inhibiting transpeptidase that cross links the components of the cell wall

Question 24

are beta lactams bacteriostatic or cidal

Answer 24

cidal

Question 25

what are beta-lactamases

Answer 25

bacterial enzymes made by bacteria that hydrolyze the beta lactam ring

Question 26

what does vancomycin

Answer 26

inhibits peptidoglycan cross linking | but not a beta-lactam

Question 27

is vancomycin a beta lactam

Answer 27

no

Question 28

what does calvulanic acid do

Answer 28

inhibits beta lactamases

Question 29

what is PABA

Answer 29

a nutrient obtained from the environment that is the precursor for folate in bacteria

Question 30

what is the use of folic acid in bacteria

Answer 30

they use it to synthesized nucleic acids

Question 31

what do sulfonamides do

Answer 31

competes with PABA

Question 32

what do trimethoprim do

Answer 32

compete with dihydrofolic acid

Question 33

what are the folic acid inhibitors

Answer 33

sulfonamides and trimethoprim

Question 34

why are sulfonamides and trimethoprim usually taken together

Answer 34

to block the sequential steps in synthesis of folic acid

Question 35

which are the three protein synthesis inhibitors that we need to know

Answer 35

chloramphenicol tetracyclines macrolines

Question 36

what are the broad spectrum protein synthesis inhibitors

Answer 36

chrloramphenicol and tetracyclines

Question 37

what are the moderate spectrum protein synthesis inhibitors

Answer 37

macrolides

Question 38

what are the narrow spectrum protein synthesis inhibitors

Answer 38

we dont need to know

Question 39

how do bacteria make protein

Answer 39

from mRNA template within the 70s ribosomal complex (50s + 30s) tRNA (t6) transfers amino acids (transpeptidation)

Question 40

what is transpeptidation

Answer 40

when tRNA (t6) transfers an amino acid to the growing amino acid chain

Question 41

how does chloramphenicol work

Answer 41

bind to the 50s subunit and block transpeptidation

Question 42

how do macrolides work

Answer 42

bind to the 50s subunit and block transpeptidation

Question 43

how do tetracyclines work

Answer 43

bind to the 30s subunit and prevent binding of incoming DNA

Question 44

where do aminoglycosides bind

Answer 44

30s ribosomal subunit

Question 45

what do aminoglycosides do

Answer 45

block initiation of 30s complex cause misreading of mRNA template inhibit translocation

Question 46

why doesnt chloramphenical hurt human cells

Answer 46

it does not bind to the 80s subunit, only the 70s

Question 47

why doesnt PABA inhibitors affect humans

Answer 47

humans cannot synthesis folic acid from paba

Question 48

what are 4 ways bacteria create resistance

Answer 48

drug inactivation (b-lactamases) alteration of binding site alteration of metabolic pathway (use folic acid from enviro instead of PABA) reduced drug accumulation (efflux)

Question 49

what is stevens-johnson syndrome and toxic epidermal necrolysis

Answer 49

rare condition where the skin becomes detached from the underlying tissue and sloughs off the body due to antibiotics