LEARN ANTIBIOTICS AND THEIR TARGET

Question 1

What are the group of the B lactams

Answer 1

Penicillin
Carbapenems
Cephalosporins

Question 2

What do B lactams target?

Answer 2

Cell wall, they block Penicillin binding protein (transpeptidase) meaning prevent X linking of the peptide side chains on NAM.
Get Incorporated into peptide chain, No cell wall cell bursts
They also stimulate autolysins which are enzymes found inside the bacteria which break the cell wall..

Question 3

What do Glycopeptides target? (Teicoplanin, Vancomycin)

Answer 3

Cell wall,
they target gram positive bacteria only
They prevent the enzyme glycosylase enzyme from adding PG monomer on to the PG chains.
ALSO binds to the last two aminoacids (Terminal D-ala,d-ala) on peptide side chain of monomer on outer surface cytoplasm membrane

Question 4

What do POLYMYXINS target (COLISTIN), they are positively charged cations

Answer 4

cell membrane, only targets gram negative bacteria.
They bind to the lipopolysaccharide (Lipid A)
they disrupt the cytoplasmic contains.

Question 5

What do LIPOPETIDES target (Daptomycin) Cubicin

Answer 5

They target gram positive bacteria

they act on cell membrane

Question 6

Classes of antibiotics that target protein synthesis?

Answer 6

Marcolides
Steprogranms
Lincosamides
Aminoglycosides
Tetracycline
Choramphenol

Question 7

What do Fluoroquinolnes target? (Ciplofloxacin, Levofloxacin)

Answer 7

DNA replication
They target DNA gyrase needed to remove the supercoiling so that DNA replication can proceed.
Topoisomerase (IV/4); needed to separated the two new interlinked daughter DNA MOLECULES- DNA breaks…

Question 8

Tetracyclines e.g. doxycycline

Answer 8

Protein synthesis
Binds reversibly to the A site (acceptor) on the 30S sub unit. inhibits binding of tTRNA to A site,
Binds reversibly so it’s bacteriostatic (inhibits growth)

Question 9

Aminoglycosides (Genatamicin, Erythromycin)

Answer 9

Inhibit proteinsynthesis
Bind irreversible to the a A site on the16s (30s subunit) prevent formation of initiation complex
They cause misreading of codon along the ,mRNA, they also increase permeability
BACTERICIDAL (irreversible)