The Biochemistry Of Antibiotics; From Serendipity To Targeted Discovery Flashcards Preview

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Flashcards in The Biochemistry Of Antibiotics; From Serendipity To Targeted Discovery Deck (28):
1

What's bacteriocidal?

Antibiotics that kill bacteria

2

Example of bacteriocidal?

Penicillins

3

What's bacteriostatic?

Antibiotics that block growth

4

Examples of bacteriostatic antibiotics?

Tetracyclines
Sulphonamides

5

Who first discovered penicillin?

Ernest Duchesne (French med student) in 1896

6

First true antibiotic?

Penicillin

7

Who rediscovered penicillin?

Alexander Fleming in 1928

8

Where did Alexander Fleming discover penicillin?

Clarence memorial wing, st Mary's hospital, London

9

Where did the fungus come from?

Freeman's lab

10

What was Florey's experiment?

To determine how much penicillin is needed to destroy E.coli in mice

11

Method of Florey's experiment?

1. Injected peritoneal injection of e.coli 1 day prior to treatment
2. 8 hourly injections of penicillin for first 36 hrs, then longer intervals (first few hours, mice sick), as experiment progressed, health improved (4 day treatment- 21/24 mice survived)

12

Who isolated penicillin notatum?

Fleming

13

What was penicillin most effective for during the war?

Treating staphyloccus

14

Following the war, was penicillin effective in treating?

Rheumatic fever and syphilis

15

What is used in the production of cheese and various meats?

Several species of penicillium

16

What are the 5 main targets of antibiotic action?

1. Inhibition of cell wall synthesis (eg penicillin)
2. Inhibition of protein synthesis
3. Inhibition of DNA or RNA synthesis
4. Inhibition of folate synthesis
5. Membrane disruption

17

What does penicillin do and who discovered it?

Inhibits the bacterial cell wall synthesis- discovered by Joshua lederberg (Nobel prize 1958)

18

Essentially, what happens in penicillin?

Cytoplasm escapes as no cell wall

19

What is a primary component of the bacterial cell wall?

Peptidoglycan (provides support and rigidity)

20

What enzyme forms the cell wall- through cross linking peptidoglycans?

DD-transpeptide (also called a penicillin binding protein)

21

What is penicillin similar to?

D-Ala-D-Ala

22

Example of inhibition of protein synthesis?

Aminoglycosides

23

What do antibiotics do in inhibition of protein synthesis?

Bind to bacterial RNA, disrupt ribosomal structure leading to mistranslated proteins that can misfold leading to cell death- incorporation of misgolded membrane proteins into cell envelope can lead to increased drug uptake

24

Example of inhibition of DNA or RNA synthesis?

Rifamycin class of antibiotics (these antibiotics bind to actively transcribing RNA polymerase enzyme

25

Example of the inhibition of folate synthesis (antimetabolites)?

Sulfonamides competitively inhibit dihydropteroate synthetase (an enzyme that converts P-aminobenzoic acid (PABA) into folic acid

26

What is the most widespread target of clinical utility in antibiotics?

Membrane disruption

27

Example of antibiotic membrane disruption?

Lipopeptide antibiotics (eg daptomycin)

28

What happens with daptomycin?

It's a peptide sequence to which a fatty acid moiety is covalently attached (unclear mechanism of action- likely to include membrane disruption and loss of membrane potential)