Antibiotics

Question 1

What are antimicrobials?

Answer 1

a broad category of agents that are used to treat or prevent infections caused by microorganisms

Question 2

What are antibiotics?

Answer 2

specific class of antimicrobial that specifically target bacteria.

Question 3

Three types of antibiotics?

Answer 3

Bacteriostatic, bactericidal, bacteriolytic

Question 4

Bacteriostatic drugs?

Answer 4

Prevent growth of microorganism

Question 5

Bactericidal drugs?

Answer 5

Kill microorganisms

Question 6

Bacteriolytic drugs?

Answer 6

Lyse–> break down/degreade the microoganism

Question 7

What happens to the OD after bacteriostatic antibiotics are added and why?

Answer 7

SLight increase–> could be due to size of cells increasing, or metabolic products contributing to it

Question 8

What happens to the OD after bactericidal antibiotics are added and why?

Answer 8

Constant–> bacteria are not fragmented and so are still there

Question 9

What happens to the OD after bacteriolytic antibiotics are added and why?

Answer 9

Drops–> bacteria fragments

Question 10

Example of a bacteriolytic antibiotic?

Answer 10

Lysozyme

Question 11

How does a lysozyme work?

Answer 11

Catalyses hydrolysis of B1-4 glycosidic links in the cell walls peptidoglycans
Cell bursts bc of osmotic pressure

Question 12

Why was drug selectivity developed for antibiotics and an example?

Answer 12

So they could target bacteria but not humans
e.g. cell wall

Question 13

What is the bacterial cell wall made up of?

Answer 13

Peptidoglycan

Question 14

What is the fungal cell wall made up of?

Answer 14

Chitin

Question 15

Examples of cell wall synthesis inhibitors?

Answer 15

Penicillin, glycopeptides, cephalosporins, carbapenems
PGCC

Question 16

Nucleotide synthesis inhibitor example?

Answer 16

Sulphonamides
FOSul

Question 17

DNA rep inhibitors?

Answer 17

Quinolones
QUINrep

Question 18

Protein synthesis inhibitor example?

Answer 18

Macrolids, aminoglycosides, lincosamides, tetracyclines
MALT

Question 19

How does penicillin work?

Answer 19

Make existing peptidoglycan wall weaker–> cell bursts as a result of osmotic pressure

Question 20

What do sulphonamides target?

Answer 20

Folic acid DNA precursors

Question 21

Which protein synthesis inhibitors target the 30S subunit?

Answer 21

Tetracyclines and aminoglycosides

Question 22

What does vancomycin rpevent?

Answer 22

Formation of the peptidoglycan layer

Question 23

What part of cell wall inhibitors is the functional unit?

Answer 23

Beta-Lactams

Question 24

How does the beta lactam ring work?

Answer 24

Mimics the D-Ala AAs of the peptidoglycan wall that
Binds to transpeptidase enzyme instead
Cell wall is v weak as the bonds between the AA chains are not made

Question 25

How did bacteria acquire resistance to beta lactam-containing antibiotics?

Answer 25

They developed beta lactamases

Question 26

What is the "last resort" class of antibiotics?

Answer 26

Vancomycin

Question 27

Issue with vancomycins?

Answer 27

Can cause nephron toxicity

Question 28

What infections can cell wall inhibitors treat?

Answer 28

Bone and joint, respiratory, UTI, skin, heart, meningitis

Question 29

How does sulfonamides target folic acid precursors?

Answer 29

Prevent formation of dihydrofolic acid from pteridine and PABA by inhibiting dihydrofolate synthase