Aspirin & Penicillin

Question 1

formula for aspirin

Answer 1

salicylic acid + acetic anhydride –> acetylsalyclic acid + acetic acid

Question 2

recrystallisation

Answer 2

1. dissolve compound in a minimum amount of hot solvent
2. allow the solution to cool to room temperature so that crystals form slowly
3. filter crystals with suction and wash with fresh, cold solvent

Question 3

uses of aspirin

Answer 3

pain reliever, fever reducer, anticoagulant

Question 4

exception for taking aspirin

Answer 4

aspirin should not be taken if the illness is viral

Question 5

how does aspirin work?

Answer 5

aspirin prevents the COX from producing prostaglandins, which comes from physical trauma

Question 6

aspirin as an anticoagulant

Answer 6

prevents blood from clotting by slowing down clumping of platelets

Question 7

how do you manipulate the solubility of aspirin?

Answer 7

modified to salt in order to increase solubility (e.g. in COOH, H+ is replaced by Na+ as it is more soluble in water due to stronger attractive forces to dipoles in the water molecule)

Question 8

synergistic effect of aspirin and alcohol

Answer 8

drinking alcoholic drinks increases risk of stomach bleeding and each drug has a higher medicinal effect when taken combined

Question 9

what is penicillin made of?

Answer 9

penicillin is produced by fungi/moulds that are under stress to treat bacterial infections

Question 10

virus

Answer 10

small capsules of DNA that require a host cells in oder to replicate

Question 11

what does penicillin do?

Answer 11

stops the growth and reproduction of bacteria

Question 12

3 significances of the beta-lactam ring

Answer 12

• binds to PBP and prevents cell walls from cross-linking
• ring is sterically strained
• ring breaks up and reacts easily

Question 13

how is penicilling modified to enhance medicinal effect?

Answer 13

modifications can be made to the side chains (R group)

Question 14

how does penicillin work?

Answer 14

• when bacteria divide to make 2 identical cells, new cell walls are required for the two cells to separate and to have structure and protection
• requires cell walls to prevent the rupture of bacterium’s structure
• cell wall requires cross linking to prevent osmosis

Question 15

what enzymes destroy penicillin?

Answer 15

penicillinase or beta-lactamase by breaking the beta-lactam ring and prevents penicillin from binding to the PBP

Question 16

why must perscriptions be finished?

Answer 16

because the weaker bacteria would be killed but the stronger bacteria would remain and reproduce a whole population resitant to penicillin