Question

19. Why are receptors and substrates sometimes explained in terms of locks and keys?

26. Why is a drug

Answer 1

19.

Enzymes have specific active sites wich allow substrate to bind to them . This active site has a unique geometrical shape that fits only the perfect substrate . So the lock and key mechanism was provided where enzyme is the lock and substrate is the key. So only a particular key can open the lock that is only a particular substrate can bind to the enzyme.

26.

Our body is actually chiral in nature so when we take a drug the enantiomer of the drug behaves differently because enantiomers behave differently in chiral environments. There may be chemical chages because of which a R enantiomer may behave as S enantiomer and both of them behave as different drugs.

29.

On treating a fatal illness a drug having 50% chance of treating the illness should be taken because atleast it provides 50% chance of survival compared to 10% chance of causing fatal toxic reaction which is very less compared to the chances of survival . If it is not used then it will ultimately lead to death so it is better to take the drug.

On treating acne a drug having 50% chance of treating acne but 10% chance of causing toxic chemical reaction should not be taken because acne is not a fatal disease so we do not have to take the risk of using a drug which may harm us by causing fatal toxic chemical reactions.

32.

No I wouldn't believe the herbalist because any kind of drug made from a herb or other chemicals will have some kind of side effect but the proportion of side effect varies . So it is not possible to have a herb that can treat headaches without any side effects or toxicity.

33.

Yes it is possible to use risk-benefit decision making in determining that whether or not herbal medicines should be used in US. Actually herbal medicines or better known as Ayurvedic medicines ( in India) have lesser side effects and have more benefits rather than risks compared to some of the drugs made from other chemicals. So it would be a better option to use herbal medicines in some treatments.Actually US is shifting towards old Indian treatments of Ayurvedic medicines hence it is definitely possible that herbals are used in US