Monday, December 18, 2006

Monday's Molecule #6

Name this molecule. You must be specific. We need the exact name. Bonus points for explaining why this molecule caused such a controversy in biochemistry. (Hint: it has something to do with the green carbon atoms.) Comments will be blocked for 24 hours. Comments are now open.

See Dunbar's answer in the comments for the correct answer with a good explanation of why Krebbs got in trouble and why his Nobel Prize was questioned by some.


  1. 2R,3S-Isocitrate; when Kreb proposed his eponymous cycle, he said that citrate, through aconitase, would yield stereospecific isocitrate. That is, there would be no chemical change to the carbon contribution from acetyl-CoA (the carbon atoms labelled green), but all the chemical change would happen on the carbons contributed by oxaloacetate. This was ridiculed by the establishment, with the reasoning that since citrate had no chiral atoms, chemical modification should happen to both the acetyl-CoA contribution and the oxaloacetate contribution. But this reasoning was flawed, because aconitase could recognise the different contributions through a three point attachment. I guess I should stop here...