O- optical isomerism

Question 1

Which enantiomer, D or L, + or -, rotates the plane-polarised light clockwise?

Answer 1

D/ +

Question 2

One of the optical isomers of thalidomide was an effective sedative and antiemetic.
Explain the terms.

Answer 2

• sedative- sleepy/ drowsiness
• antiemetic- drug that reduces vomitting

Question 3

One optical isomer of thalidomide was teratogenic. Explain the term.

Answer 3

• drug that disturbs development of an embryo/ fetus
• caused birth defects/ miscarriage

Question 4

Some drugs act as competitve inhibitors of enzymes. Explain how they work.

Answer 4

• bind to a.s. of enzyme
• prevents subatrate from binding

Question 5

Why would only one optical isomer be effective but not the other?

Answer 5

• only one will fit into a.s.
• forms attractions to enzyme at a.s.
• other isomer = wrong shape

Question 6

What equipment is used to measure optical rotation?

Answer 6

polarimeter