Monday, April 16, 2012

Monday's Molecule #166

This is another one of those molecules where you have to pay close attention to the structure. There are many similar molecules and you won't win unless you are very specific. You don't need the full IUPAC name. You do need to identify the function of this molecule.






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UPDATE: The molecule is heme a, a component of cytochrome a and cytochrome a3. The cytochromes are cofactors in oxidation-reduction reactions where the heme group serves as an electron donor or acceptor. Today's winner is Raul A. Félix de Sousa. Several anonymous/pseudoanonymous respondants were also correct.

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. 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


  1. I believe that molecule is Heme A

  2. Heme a, found in cytochromes, important for oxidative phosphorylation along mitochon membrane

  3. "Heme A was first isolated by the great German biochemist Otto Warburg in 1951 and shown by him to be the active component of the integral membrane metalloprotein cytochrome c oxidase" - Wikipedia

  4. Heme A, it is found in cytochrome proteins were it functions to bind metal ions used in binding oxygen and electron transfers.

  5. Heme A in its oxidised form. Cofactor for cytochrome C oxidase (important respiratory protein) and target of cyanide and other respiratory poisons.

  6. Raul A. Félix de SousaMonday, April 16, 2012 7:58:00 PM

    Molecule # 166 is Heme A, in its oxidised form (i.e. with Fe3+) . It binds to Cytochrome c oxidase, an essential component of the electron transport chain in mitocondria and bacteria, central the process of aerobic respiration.

  7. The molecule is Heme A, which is found in cytochrome a and a3 as part of the cytochrome c oxidase complex at the end of the electron tranport chain. The iron atoms found in the middle of the two Heme A molecules play a role in transporing electrons from cytochrome c to the O2 molecules in order to allow the formation of water and the tranport of 4 hydrogen ions across the inner membrane of the mitochondria.
    (UofT Undergraduate)

  8. Heme a

    It is the heme group of cytochromes a and a3 in complex IV (cytochrome c oxidase) of the electron transport chain. It participates in the transfer of electrons from cytochrome c to oxygen.