Antibiotic Chemistry

Question 1

What are the 6 antibacterial mechanisms of action

Answer 1

inhibition of bacterial cell wall synthesis
inhibition of protein synthesis
inhibition of nucleic acid transcription and replication injury to plasma membrane
inhibition of synthesis of essential metabolites
miscellaneous

Question 2

what happens in antibacterial drug action

Answer 2

inhibition of cell wall synthesis
inhibition of nucleic acid replication and transcription injury to plasma membrane
kill bacteria by damaging their cell membranes
inhibition of protein synthesis
kill or impair the growth of bacteria by preventing them from making proteins
inhibition of synthesis of essential metabolites disrupt essential bacterial metabolic pathways
(antimetabolites)

Question 3

what is our body made out of?

Answer 3

made out of eukaryotic cells, Muti-celled

Question 4

what is bacteria body made out of?

Answer 4

made out of Prokaryotes : Unicellular

Question 4

describe the structure of bacteria

Answer 4

they have a slimy capsule made of polysaccharide
there’s a cell wall in most prokaryotes
a cell wall is a structural layer, which encapsulates bacteria , and offers structural support and protection.
Filtering capabilities

Question 5

what does a bacteria cell consist of?

Answer 5

capsule
flagella
cell wall
cell membrane
ribosome
chromosomes
nucleic region
flagellum

Question 6

what’s the difference between gram positive and gram negative

Answer 6

gram -negative is thin
gram-positive is thick

Question 7

what is B-1,4-glycosidic bonds the site of?

Answer 7

site of cleavage by lysozyme with a reducing end

Question 8

describe the segments of NAM and NAG

Answer 8

Segments in a alternating pattern

Question 9

Peptidoglycan

Answer 9

cross-linked by short, four to five amino acids long , or tetrapeptide chains, protruding from NAM subunits

Question 9

what is transpeptidation

Answer 9

the pentapeptide chains reach out and link to chains from the neighbouring strands .
DD-transpeptidases or penicillin binding proteins highly selective

Question 10

inhibition of bacterial cell wall synthesis

Answer 10

B-lactam antibiotics such as penicillin and cephalosoporins, have a b-lactam ring in their structure

b-lactam antibiotics are bactericidal and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls

Question 11

give examples of penam

Answer 11

Amoxicillin , Benzylpenicillin , co-amoxiclav , flucloxacillin, penicillin V, Tazocin , Pivmecillinam, Temocilllin
don’t have an

Question 12

give examples of cefam

Answer 12

cefalexin, cefixime , cefoatimne, ceftazidime, ceftriaxone , cefuroxamine, ciprofloxamine

Question 13

penem

Answer 13

have a double bond

Question 14

carbapenem

Answer 14

ertapamen, meropenem

Question 15

monobactam

Answer 15

aztreonam

Question 16

structure activity relationship SAR

Answer 16

R group may be varied with enzymes and semi-synthetic methods
EWG- N less nucleophilic bulky group - steric
hinderance of B-lactamase

Question 17

b-lactam ring

Answer 17

b-lactam ring may be opened with OH,NH2,SHeg H2O

Question 18

carboxylic acid

Answer 18

normally negatively charged forming salt bridge in enzyme pocket
involved in ionic interaction
with N of binding site

Question 19

the smaller the ring

Answer 19

the more reactive

Question 19

b-Lactam structures

Answer 19

penam, amoxicillin, cefam,,cefaların, penem, carbopenem, ertapamen, monobactam aztreonam

Question 20

mechanism of action

Answer 20

cleavage of the D-alanyl-D-alanine bond of a peptide unit precursor acting as carbonyl donor , the release of the carbonyl -terminal D-alanine , and the formation of the acyl-enzyme

the breakdown of the acyl-enzyme intermediate and the formation of a new peptide bond between the carbonyl of the D-alanyl moiety and the amino group of another peptide unit

Question 21

DD–transpeptidase mechanism

Answer 21

there are always key amino acids in charge of this interaction
Ser35

Question 21

what are the 2 mechanism of action

Answer 21

transpeptidase cross-linking
penicillin inhibition