Post your answer in the comments. I'll hold off releasing any comments for 24 hours. The first one with the correct answer wins. I will only post correct answers to avoid embarrassment. This is your last chance to enter the Christmas draw for a free textbook!
There could be two winners. If the first correct answer isn't from an undergraduate student then I'll select a second winner from those undergraduates who post the correct answer. You will need to identify yourself as an undergraduate in order to win. (Put "undergraduate" at the bottom of your comment.) Every undergraduate who posts a correct answer will have their names entered in a Christmas draw. The winner gets a free autographed copy of my book! (One entry per week. If you post a correct answer every week you will have ten chances to win.)
Some past winners are from distant lands so their chances of taking up my offer of a free lunch are slim. (That's why I can afford to do this!)
In order to win you must post your correct name. Anonymous and pseudoanonymous commenters can't win the free lunch.
Winners will have to contact me by email to arrange a lunch date.
UPDATE: The molecule is thyrotropin-releasing hormone. It's derived from a long precursor protein containing multiple repeats of the tripeptide Glu-His-Pro.
The winner is Joseph C. Somody.
I'll announce the undergraduate winner of my textbook on Christmas day.
Winners
Nov. 2009: Jason Oakley, Alex Ling
Oct. 17: Bill Chaney, Roger Fan
Oct. 24: DK
Oct. 31: Joseph C. Somody
Nov. 7: Jason Oakley
Nov. 15: Thomas Ferraro, Vipulan Vigneswaran
Nov. 21: Vipulan Vigneswaran (honorary mention to Raul A. Félix de Sousa)
Nov. 28: Philip Rodger
Dec. 5: 凌嘉誠 (Alex Ling)
Dec. 12: Bill Chaney
