Antibiotics and Anti-fungals

Question 1

Important step in production of bacterial DNA synthesis

Answer 1

Production of tetrahydofolate

Question 2

Important first step in production of THF

Answer 2

Paraaminobenzoate-> dihydropteroate

Question 3

Enzyme for conversion of PABA to DHOp

Answer 3

DHOp synthase

Question 4

Intermediate between DHOp and THF

Answer 4

Dihydrofolate

Question 5

Enzyme in conversion of DHF to THF

Answer 5

DHF reductase

Question 6

Important enzyme in bacterial DNA replication

Answer 6

DNA gyrase ( like our topoisomerase as releases tension)

Question 7

Enzyme in bacterial synthesis

Answer 7

RNA polymerase- is different to ours but still does same job of producing RNA from DNA template

Question 8

How is bacterial ribosome different to ours

Answer 8

Smaller

Question 9

5 antibiotic classes for intracellular mechanisms

Answer 9

Sulphonamides
Trimethoprim
Fluoroquinolones
Rifamycins
Macrolides

Question 10

MOA of sulphonamides

Answer 10

Targets DHOp synthase

Question 11

MOA of trimethoprim

Answer 11

Targets DHF reductase

Question 12

MOA of fluoroquinolones

Answer 12

Targets DNA gyrase

Question 13

MOA of rifamycins

Answer 13

Targets bacterial RNA polymerase

Question 14

MOA of macrolides

Answer 14

Inhibit bacterial ribosomes

Question 15

Peptidoglycan synthesis

Answer 15

Pentapeptide added to NAM which associates with NAG to form PtG

Question 16

How is PtG transported across membrane to form cell wall

Answer 16

bactoprenol

Question 17

What forms links between PtG pentapeptides

Answer 17

Transpeptidases

Question 18

5 drug classes targeting bacterial wall synthesis

Answer 18

Glycopeptides
Bacitracin
Beta-lactams
Lipoproteins
Polymyxins

Question 19

MOA of glycopeptides

Answer 19

Binds to pentapeptides preventing PtG synthesis

Question 20

MOA of bacitracin

Answer 20

Inhibits bactoprenol regeneration

Question 21

MOA of beta lactams

Answer 21

Bind covalently to transpeptidases inhibiting PtG incorporation

Question 22

MOA of lipopeptide

Answer 22

Disrupt Gram +ve cell walls

Question 23

MOA of polymyxins

Answer 23

Bind to LPS and dsirupt gram -ve cell membranes

Question 24

Causes of antibiotic resistance

Answer 24

Overprescription
Livestock farming
Lack of regulation in some areas in world
lack of development in antibiotic

Question 25

5 methods of resistance

Answer 25

Production of destruction enzymes
Producing different target to drug that is resistant to action of drug
Altering the enzyme targeted by the drug which drug is ineffective to
Alterations in drug permeation to cell
Increase the amount of enzymes to decrease efficacy of the drug

Question 26

Example of production of destruction enzymes

Answer 26

Beta-lactamase can hydrolyse the C-N bond of beta lactam ring

Question 27

Can all penicillins fight against all bacteria

Answer 27

No there is variation amongst the classification in their efficacy against gram -ve and +ve

Question 28

Example of producing different target to drug that is resistant to action of drug

Answer 28

Ecoli produce different DHF reductase that is resistant to trimethoprim

Question 29

Example of altered enzyme

Answer 29

S aureus has mutation in ParC region of topoisomerase IV which is resistant to quinalones

Question 30

Example of alterations in drug permeation

Answer 30

Reduction in aquaporins and increased efflux systems

Question 31

What bacteria is alterations in drug permeations more relevant

Answer 31

Gram -ve

Question 32

Example of hyperproduction of the target enzyme

Answer 32

E coli increase amount of DHF reductase making trimethoprin less effective

Question 33

4 classifications of fungal infections

Answer 33

Superficial
Dermatophyte
Subcutaneous
Systemic

Question 34

2 types of antifungals

Answer 34

Azoles

Polyenes

Question 35

MOA of azoles

Answer 35

Inhibit P-450 dependent enzymes involved in membrane sterol synthesis

Question 36

MOA of polyenes

Answer 36

Interact with cell membrane sterols forming membrane channels