Stereochemistry, Enantiomerism and Racemic Mixtures Flashcards Preview

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Flashcards in Stereochemistry, Enantiomerism and Racemic Mixtures Deck (30)
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1

Click on the molecule that is one half of a racemic mixture

Study on!!!!!

2

----- is the study of the three-dimensional structure of molecules

Stereochemistry

3

The division of stereochemistry that deals with molecules that have a center of three-dimensional asymmetry is known as:

Chirality

4

Carbon binds to --- different atoms

4

5

In biologic systems, the fact that molecules that have a center of three-dimensional asymmetry generally stems from the ----- bonding of carbon

Tetrahedral

6

----- are chiral molecules that are non-superimposable mirror images of one another

 

Enantiomers

7

A molecule with one chiral carbon will exist as ----- enantiomers

Two

8

The more chiral carbons in a molecule, the more enantiomers that are created

True

9

Recall that ----- are chiral molecules that are non-superimposable mirror images of one another

 

Enantiomers

10

Look at your hands. On each hand, you most likely have a palm, thumb, and four fingers. Although your hands are mirror images of each other, you cannot superimpose one on top of the other.

While the left and the right hand are constructed from the same building blocks, they are not identical in all respects. These principals apply to chiral compounds

Thanks

11

Enantiomers in solution are distinguished from each other by the direction they ----- when exposed to polarized light

"rotate"

12

The ----- enantiomer (+) rotates clockwise.

Dextrorotatory (D)

13

The ----- enantiomer (-) rotates counterclockwise

Levorotatory (L)

14

Understand that optical rotation does not necessarily describe the ----- arrangement of the atoms on the chiral carbon

Spatial arrangement

15

Understand that optical rotation does not necessarily describe the spatial arrangement of the atoms on the chiral carbon. Instead, we use the Rand S designations to describe the ----- of a specific stereocenter within a molecule

"orientation"

16

A molecule with more than one chiral carbon will have multiple R and/or S designations in the chemical name - one for each ----- carbon

Chiral carbon

17

A ----- mixture contains two enantiomers in equal amounts

Racemic mixture

18

About what proportion of the drugs we administer are enantiomers

 

One third (1/3)

19

About 1/3 of the drugs we administer are enantiomers, and just about all of these are prepared as ----- mixtures

Racemic mixtures

20

About one-third of the drugs we administer are enantiomers, and just about all of these are prepared as racemic mixtures. Some exceptions include ----- and -----, which are prepared as single enantiomers

Levobupivacaine and Ropivacaine

21

Examples of Racemic Mixtures include:

  • Ketamine
  • Thiopental
  • Methohexital
  • Isoflurane
  • Desflurane
  • Mepivacaine
  • Prilocaine
  • Bupivacaine
  • Morphine
  • Methadone
  • Ibuprofen
  • Ketorolac

22

You have no doubt learned about the "lock and key" theory that can be applied to enzymes and substrates or receptors and their agonists. This theory assumes that physiologic systems are intrinsically -----.

Stereospecific

23

You have no doubt learned about the "lock and key" theory that can be applied to enzymes and substrates or receptors and their agonists. This theory assumes that physiologic systems are intrinsically stereospecific. Therefore, drugs that exist as enantiomers often function as -----.

2 different drugs

24

You have no doubt learned about the "lock and key" theory that can be applied to enzymes and substrates or receptors and their agonists. This theory assumes that physiologic systems are intrinsically stereospecific. Therefore, drugs that exist as enantiomers often function as 2 different drugs - with ----- affinities for the target receptor

"different "

25

You have no doubt learned about the "lock and key" theory that can be applied to enzymes and substrates or receptors and their agonists. This theory assumes that physiologic systems are intrinsically stereospecific. Therefore, drugs that exist as enantiomers often function as 2 different drugs - with different affinities for the target receptor and ----- side effects

"different"

26

Clinical Examples: Which is less cardiotoxic?

A. S-bupivacaine (levobupivacaine)

B. R-bupivacaine

C. the racemic mixture

 

S-bupivacaine (levobupivacaine)

27

Clinical Examples: Which enantiomer of Ketamine is less likely to cause emergence delirium?

A. S enantiomer

B. R enantiomer

S enantiomer

[The S enantiomer of ketamine is less likely to cause emergence delirium than the R form]

28

Clinical Examples: Which enantiomer of Ketamine is more potent?

A. S enantiomer

B. R enantiomer

S enantiomer

[The S enantiomer of Ketamine is more potent than the R form]

29

Click on the molecule that is one half of a racemic mixture

Chirality is a division of stereochemistry. It deals with molecules that have a center of three-dimensional asymmetry. In biologic systems, this type of asymmetry generally stems from the tetrahedral bonding of carbon-carbon binds to 4 different atoms

A molecule with 1 chiral carbon will exist as 2 enantiomers. The more chiral carbons in a molecule, the more enantiomers that are created. A racemic mixture contains 2 enantiomers in equal amounts

30

References:

 

Hemming s. Pharmacology and Physiology for Anesthesia: Foundations and Clinical Application. 1st ed. 2013. p. 28-29 . Flood. Stoelting's Pharmacology & Physiology in Anesthetic Practice. 5th ed. 2015. p. 38-41.