McMurry (Kap.5,12) Flashcards
does enantiomers have the same biological properties?
NO, they have the same physical properties, but for example:
(-) enantiomer of limonene has the odor of pine trees.
(+) enantiomer of limonene has the odor of oranges and lemons.
AND they have different optical activity. One enantiomer rotate the light (-) direction and the other rotate the light (+) direction, same amount.
One enantiomer has to be the R configuration and one has to be the S.
Why do different enantiomers have different biological properties?
To have a biological effect, a substance must fit into an appropriate receptor that has an exactly complementary shape.
biological receptors are chiral, therefore only one enantiomer of a chiral substrate can fit.
What does it mean if a molecule is prochiral?
Meaning if it can convert from achiral to chiral in a single chemical step.
An sp3 hybridized atom is prochiral if changing one of its attached atoms, a chirality center occurs.
R configuration chirality center is called a pro-R and the same bur for S-configuration for the pro -s.
What is Re and Si?
A prochiral sp2 hybridized atom has two faces described as either Re and Si.
If the arrangement is clockwise, it would be termed Re; if it is counterclockwise, it would be termed Si.
What is meant with the term “chiral environment”?
A chiral environment is when chiral molecules are around, affecting how other molecules behave. Chiral molecules cannot be matched with their mirror images, similar to how your left hand is different from your right hand.
In this environment, reactions may produce more of one form of a chiral molecule (let’s call it molecule A) instead of the other form (molecule B). This is important in living things because many biological molecules are chiral.
Enzymes usually interact with just one form of a chiral molecule, which leads to specific chemical reactions. Overall, a chiral environment changes how molecules interact and react, which is very important in chemistry and biology.
