Monday, June 24, 2013

Monday's Molecule #206

Last week's molecule was myricyl palmitate, the major component of beeswax [Monday's Molecule #205]. The winner was Bill Chaney. There was no undergraduate winner.

Today's molecule is a very common molecule shown in a somewhat unusual conformation. (It's the conformation of the molecule when it's bound to a certain enzyme.) Identify the molecule (common name only). Can you describe the conformation?

Email your answers to me at: Monday's Molecule #206. I'll hold off posting your answers for 24 hours. The first one with the correct answer wins. I will only post mostly correct answers to avoid embarrassment. The winner will be treated to a free lunch.

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 email message.)

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. Please try and beat the regular winners. Most of them live far away and I'll never get to take them to lunch. This makes me sad.

Comments are now open.

UPDATE:The molecule is N-acetylmuramic acid (MurNAc) (technically, it's the ionized form of the acid). Michael Florea (undergraduate) was the first person to email the correct answer. The conformation shown in the figure is the "half-chair" conformation found when a MurNAc residue is bound to the active site of lysozyme. (Brian Shewchuk was the first one to recognize the conformation.) Bacterial cell wall polysaccharides consist of alternating GlcNAc and MurNAc residues and lysozyme attacks cell walls by digesting this polysacharide.

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
Dec. 19: Joseph C. Somody
Jan. 9: Dima Klenchin
Jan. 23: David Schuller
Jan. 30: Peter Monaghan
Feb. 7: Thomas Ferraro, Charles Motraghi
Feb. 13: Joseph C. Somody
March 5: Albi Celaj
March 12: Bill Chaney, Raul A. Félix de Sousa
March 19: no winner
March 26: John Runnels, Raul A. Félix de Sousa
April 2: Sean Ridout
April 9: no winner
April 16: Raul A. Félix de Sousa
April 23: Dima Klenchin, Deena Allan
April 30: Sean Ridout
May 7: Matt McFarlane
May 14: no winner
May 21: no winner
May 29: Mike Hamilton, Dmitri Tchigvintsev
June 4: Bill Chaney, Matt McFarlane
June 18: Raul A. Félix de Sousa
June 25: Raul A. Félix de Sousa
July 2: Raul A. Félix de Sousa
July 16: Sean Ridout, William Grecia
July 23: Raul A. Félix de Sousa
July 30: Bill Chaney and Raul A. Félix de Sousa
Aug. 7: Raul A. Félix de Sousa
Aug. 13: Matt McFarlane
Aug. 20: Stephen Spiro
Aug. 27: Raul A. Félix de Sousa
Sept. 3: Matt McFarlane
Sept. 10: Matt Talarico
Sept. 17: no winner
Sept. 24: Mikkel Rasmussen
Oct. 1: John Runnels
Oct. 8: Raúl Mancera
Oct. 15: Raul A. Félix de Sousa
Oct. 22: Mikkel Rasmussen
Nov. 12: Seth Kasowitz, Bill Gunn
Nov. 19: Michael Rasmussen
Dec. 4: Paul Clapham, Jacob Troth
Dec. 10: Jacob Troth
Dec. 17: Bill Chaney, Dima Klenchin, Bill Gunn
Jan. 14: Evey Salara
Jan. 21: Piotr Gasiorowski
March 11: Bill Gunn, River Jiang
March 18: Bill Gunn
April 8: Michael Florea
April 15: no winner
April 29: Anders Ernberg
May 6: Alex Ling, Michael Florea
May 13: Bill Chaney
June 24: Michael Florea