paper 3 option D Flashcards
how does the beta lactam ring work against bacteria?
it inhibits the enzyme transpeptidase in the bacteria that produces the cell wall. the bacteria (cells of bacteria) therfore absorbs water and bursts.
what are the bond angles in the beta lactam ring? and what would they be in an open structure?
90 degrees
120 degrees and 109.5 degrees.
how can pennicilin be modified to be effective against bacteria?
modify side chain
why does pennicilin not work on human cells?
human cells do not have cell walls.
why is diamorphine more effective in crossing the blood brain barrier than morphine or codeine?
doesnt contain hydogen bonds (hydroxyl group) so is less polar than the other two, and the blood brain barrier is non polar.
in a buffer question you are given the Ka to work with, what must you do before using the formula?
convert Ka into pKa by doing log– of the Ka.
outline two ways in which viral medication works agaisnt viruses?
examples of viral medicine?
prevents release of replicated viruses from host cell
by inhibiting viral enzymes/neuraminidases «needed to release virus»
blocks enzyme activity in host cell so that the virus cannot use it to multiply.
oseltamivir and zanamivir
suggest two reasons why chlorinated solvents should neiter be released into the atmosphere or burnd?
cause cancer and produce dioxins
explain the low and high environmental impacts of medical nuclear waste? give examples
low level nuclear waste:
emmits weak level of ionization energy and has a short life. ex: gloves/syringes
high level nuclear waste:
the reverse of everything. ex. nuclear fuel + rods.
how does aspirin work? what type of an analgesic is it?
where does it come from
mild analgesic
interferes with the production of prostaglandins at the site of injury/source of pain .
willow bark
what are opiates? examples
strong analgesics
morphine, diamorphine and codeine
Outline how codeine
can be synthesized from morphine
and another than is used to prepare diamorphine from morphine
react with methly iodide CH3I in alkaline solution
with ethanoic anyhydride
Explain why opiates are addictive
interact with opioid receptors in the brain
prevents transmission of pain impulses inside the brain
gives a feeling of pleasure/euphoria «that the person craves»
Outline the difference between the therapeutic index in animal studies and the
therapeutic index in humans
n animal studies lethal dose/LD50 AND in humans toxic dose/TD50
State the method of drug administration that gives the maximum bioavailability
intravenous so in blood stream
Explain how ranitidine (Zantac) reduces stomach acid production
prevents histamine binding to H2/histamine receptors «and triggering acid
secretion»
prevents parietal cells from releasing/producing acid
in the formula for the buffer solution, is the acid on top or at the bottom?
it is base/salt over the acid.
acid on the bottom
structurally why is the beta lactam ring good against bacteria?
Outline what is meant by the term “ring strain”.
/amine group «in ring» is «highly» reactive ✔
angles of 90° instead of 109.5/109/120° angles
ring strain refers to the instability resulting from abnormal bond angles
how do nexion and prilosec reduce the stomach acidity?
inhibit the proton pumps in the stomach directly which prevents the secretion of H+ into the stomach.
what must oseltavimir undergo in the body?
its ester group must be changed into a carboxylic group
from what is oseltamivri synthesized?
suggest an e alternative green chemistry source of shikimic acid
shikimic acid from star anise (plant)
genetically engineered bacteria/E.coli
why is cold water used to isolate aspirini from impurities?
aspirin/product has low solubility «in water» at low temperatures
compare the bioavaliabity of soluble aspirin and aspirin
«marginally» higher AND increase absorption in mouth/stomach «mucosa»
how can aspirin be converted into soluble aspirin
react with NaOH
