MCMP 824: Lecture 4

Question 1

drugs bind receptors with

Answer 1

stereoselectivity

Question 2

priorities are assigned to atoms attached to a chiral center based on

Answer 2

atomic number

Question 3

different stereoisomers have different properties why?

Answer 3

the more active isomer of a drug makes contact with more interacting groups in the receptor binding pocket

Question 4

Easson-Stedman hypothesis states that

Answer 4

the more potent enantiomer must be involved in a minimum of 3 intramolecular interactions with the receptor

Question 5

LESS POTENT ONLY INTERACTS WITH (easson-stedman hypothesis)

Answer 5

only interacts with 2 sites

Question 6

different stereoisomers have different

Answer 6

potencies

Question 7

____ drug enantiomers will have different affinities but ____ drugs will have the same

Answer 7

• BETA

- ALPHA

Question 8

enantiomers are

Answer 8

complete mirror images of each other

Question 9

are diastereomers mirror images?

Answer 9

no

Question 10

many drugs are sold as a racemic mixture with the assumption that the _____ enantiomer is inert

Answer 10

inactive

Question 11

phases that a drug can encounter prior to reaching the biologic target? (6)

Answer 11

1) drug dose
2) membrane selectivity
3) selective metabolism
4) nonspecific receptors, site of loss
5) drug receptor
6) desired response

Question 12

not all differences in activity of isomers ar due to differences in _____ with the ______

Answer 12

• interactions

- receptor

Question 13

____ ____ ____ ____ can affect a drug’s pharmacokinetics and thus biological activity

Answer 13

non-specific protein binding

Question 14

many drugs bind to ___ ___ via ___ or ____ interactions

Answer 14

• plasma proteins
• ionic
• hydrophobic

Question 15

a drug cannot partition to the target receptor unless it is?

Answer 15

free in the plasma

Question 16

protein binding can : (3)

Answer 16

1) prevent rapid drug excretion
2) limit the amount of free drug available at any given time
3) act as a sink for prolonged drug release

Question 17

interactions can be

Answer 17

stereospecific

Question 18

plasma is really good at binding ______ molecules

Answer 18

hydrophobic

Question 19

take home message: drug distribution throughout the body is complex and highly dependent on a drug’s relative (3)

Answer 19

1) lipid/water solubility
2) degree of ionization
3) tendency to bind proteins

Question 20

different stereoisomers can differ in terms of (3)

Answer 20

1) pharmacokinetics
2) bioavailability
3) toxicity

Question 21

many drug formations are ____ ___

Answer 21

racemic mixture = 50:50 mixtures of two enantiomers

Question 22

one of the enantiomers may differ from the other in terms of

Answer 22

absorption, serum protein binding, metabolism

Question 23

an inactive enantiomer may selectively trigger ______

Answer 23

toxicity

Question 24

bottom line: in general it would be preferable to administer drugs as

Answer 24

pure enantiomers

Question 25

enantiomers are ____ molecules that are ___ ___ of one another. Furthermore the molecules are ____ ____ on one another.

Answer 25

• chiral
• mirror images
• non-superimposable

Question 26

diastereomers are stereoisomers that are not ___ ___ of one another and are _____ _______. Stereoisomers with two or more ____ can be diastereomers

Answer 26

• mirror images
• non-superimposable
• stereocenters (chiral centers)

Question 27

priorities ____ > _____> _____> _____> ____> _____> ______> ______>

Answer 27

I>Br>Cl>S>O>N>C>H