"That's a great deal to make one word mean," Alice said in a thoughtful tone. "When I make a word do a lot of work like that," said Humpty Dumpty, "I always pay it extra."

Friday, 29 January 2010


I came across this word the other day and have to admit I didn’t even understand the definition. An enantiomoprh is either one of a pair of compounds (crystals or molecules) that are mirror images of each other but are not identical. How can something be a mirror image and yet not be identical. Surely by definition if it is a mirror image it must be identical (except a mirror image!!!). Ah well, it would be a bit much if I could understand all the definitions!


  1. Well that is why the first glimpse of themselves in a mirror presents a small child or an animal with a great mystery...! LOL

    With molecules I suppose it must mean that even though they are mirror images of each other, they are not interchangeable when it comes to connecting with other molecules and make up someting else. (Not that chemistry was ever "my subject", so I'm just guessing.)

  2. I'm guessing (from dredging up A-Level chemistry from the back of my mind) as I've never heard the term before, that a good example of this would be thalidamide.

    There are two versions of thalidamide that are identical apart from one is a mirror image of the other -- usually referred to as being either left or right handed.

    This means that the combination of elements within the molecule is the same but the structure is a mirror image.

    One version of thalidamide is dangerous and causes birth defects whereas the other is an effective drug. The problem was that this wasn't properly understood at the time and so the two forms were not separated. Thalidamide is making a come back, but now they are very careful to make sure they only use the correct form.

    The related, and more commonly used, word is chirality and the wikipedia pagev has some nice chemical diagram images showing exactly what I've tried to explain.

  3. Thanks, guys, you did a wonderful job at distinguisihng the difference betweena a thing and its "mirror" image: the sructure is the same but the arrangement or orientation, as Mark put it - in oreintation, the right is on the left and visa versa. As your example shows, the two forms of thalidamide, make a profoundly different impact in the human body.

    To me (a woman, not a chemist)
    I think of pinning a corsage on my dress. In the mirror it appears on one side, but in the real world, it's on the opposite shoulder.

    Maybe that's why everything is "as shouldn't be" in "Alice Through the Looking Glass".

    Hope this make some sense. Like Alice, I'm not sure....