It is written in the book, that when a chiral carbon is synthesised in the laboratory, a mixture of optical iosmers is usually formed (a racemic mixture), but when made naturally in a living sytem, it is produced as a single optical isomer.
Is this the correct explanation for why they are produced as a single isomer in living systems- because within the body, molecules are synthesised by the action of enzymes, and as these have a specific active site, the molecules will only be able to bind on that active site in one way, allowing the formation of only 1 of the possible product.
But in the lab-molecules can combine in any possible manner?
The formation of a single optical isomer naturally? watch
- Thread Starter
- 19-01-2010 15:05
- 19-01-2010 15:10
It is indeed
- 19-01-2010 15:41
Yep, thats right.
For instance a planar molecule can be attacked from either side in solution to form either isomer. But in a natural system the bond will be held in a specific position by the enzyme, so it can only be attacked from one direction.
- 19-01-2010 15:42
Enzymes in the body provide the substrates with a chiral environment in which each enantiomer interacts with differently. Often only one enantiomer can be formed, for reasons which you have already mentioned. Standard solution phase reactions we do in the lab provide no such chiral environment, but for some reactions we can sort of mimic the action of these enzymes by using a catalyst with chiral ligands. Usually though, it's easier to just use enantiomerically pure starting materials.