1. Antibiotics and Resistance: Chapter 20

Question 1

what is an example of an effective antibiotic?

Answer 1

penicillin/beta lactam drugs

Question 2

Define B (beta)-lactam drugs.
What are they?
What do they do?
What do they have?

Answer 2

antimicrobial medications
inhibit peptidoglycan synthesis
shared chemical structure called a B-lactam ring

Question 3

describe how penicillin interacts with penicillin binding proteins

Answer 3

penicillin stops the enzymes that form cross-links between peptidoglycan chains.

interfere with peptidoglycan synthesis by competitively inhibiting a group of enzymes that catalyze the formation of the peptide bridges that cross-link adjacent glycan chains. the enzymes are commonly called penicillin-binding proteins.

Question 4

Beta lactam drugs aka…

Answer 4

the family of penicillins

Question 5

The family of penicillins aka…

Answer 5

Beta lactam drugs

Question 6

What is modified in beta lactam drugs to change drug properties?

Answer 6

the side chain, not the ring

Question 7

Describe the basic structure of beta lactam drugs (2)

Answer 7

Beta lactam ring and a side chain

Question 8

Resistant bacteria produce ____ _________ that chews up the beta lactam ring

Answer 8

beta lactamase

Question 9

Resistant bacteria produce beta lactamase, which…

Answer 9

chews up the beta lactam ring

Question 10

How do resistant bacteria respond to beta lactam drugs?

Answer 10

Producing beta lactamase, which chews up the beta lactam ring

Question 11

How might a beta lactam drug avoid resistance?

Answer 11

By giving beta lactam drug + beta-lactamase inhibitor

Question 12

Giving beta lactam drug + beta-lactamase inhibitor is a way to do what?

Answer 12

Beta lactam drug avoid resistance

Question 13

what gives rise to resistance to antibiotics?

Answer 13

mutations and HGT

Question 14

what are two ways to develop resistance to antibiotics?

Answer 14

mutations and HGT

Question 15

Name four types of mutations that we studied in class

Answer 15

Silent
Missense
Nonsense
Frameshift

Question 16

what is a silent mutation?

Answer 16

does not change the AA coded

Question 17

what is a missense mutation?

Answer 17

changes the AA coded by DNA

Question 18

what is a nonsense mutation? what is the result?

Answer 18

introduces a stop codon, resulting in a shortened protein

Question 19

what is a frameshift mutation?

Answer 19

adding or deleting a number of nucleotides not divisible by 3

Question 20

a mutation occurs, adding or deleting a number of nucleotides not divisible by 3. which type of mutation has occured?

Answer 20

frameshift

Question 21

a mutation occurs, changing the AA coded by DNA. which type of mutation has occured?

Answer 21

missense

Question 22

a mutation occurs, but no change in the AA sequence is detected. which type of mutation has occured?

Answer 22

silent/synonymous

Question 23

a mutation occurs, introducing the stop codon and thereby shortening the protein being produced. which type of mutation has occured?

Answer 23

nonsense

Question 24

what does a Kirby-Bauer test indicate? how does it do so?

Answer 24

the sensitivity of a bacterial strain to medication. discs with different amounts of antimicrobial are deposited and allowed to form a concentration gradient

Question 25

what does the MIC test indicate? how does it do it? and what does MIC even stand for?

Answer 25

Minimum Inhibitory Concentration. lowest concentration of the antimicrobial medication that prevents growth of the test strain is the MIC. serial dilutions are performed with different concentrations of the antimicrobial, and cloudiness indicates growth. so, the lowest, clear conc. is the MIC