Monday's Molecule #180

It's Tuesday, so it must be time for Monday's Molecule.... Oops.¹

Last week we looked at an important intermediate in the Calvin cycle—the main pathway for fixing carbon dioxide in many species [Monday's Molecule #179]. Today we're going to look at the intermediate in another pathway. Name the molecule, the common name will do.

Discovery of this molecule, and the pathway it's involved in, was an important contribution to understanding basic metabolism in most cells. The enzyme that makes it has been characterized. It's now one of the most widely studied enzymes in biochemistry. The pathway is essential for all species, with a few minor exceptions.

This knowledge has been exploited by technology to an extent never imagined only 50 years ago. Name the technology and how it makes use of what we know about the enzyme and the pathway. For extra bonus points, explain how the molecule got it's root Japanese name.

Post your answers as a comment. I'll hold off releasing any comments 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 with a very famous person, or me.

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.)

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 invisible for 24 hours. Comments are now open.

UPDATE:The molecule is 5-enolpyruvylshikimate 3-phosphate an intermediate in the chorismate pathway and the synthesis of tryptophan, phenylalanine, and tyrosine. The enzyme that produces this product is EPSP synthase and some bacterial versionsof this enzyme are resistant to glyphosate, the active ingredient in the herbicide Roundup®.

The gene for the resistant enzyme can be inserted into crop plants making them resistant to Roundup®.

The winner would have been Ben but I can't identify that person. The winner is Raul A. Félix de Sousa.

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
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

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1. I got confused because yesterday was Simcoe Day.

Monday's Molecule #231

Monday's Molecule #230 (Jan. 27, 2014) [Monday's Molecule #230] was 2-carboxy-3-ketoarabinitol 1,5-bisphosphate. It's an intermediate in the reaction catalyzed by ribulose 1,5-bisphosphate carboxylase-osygenase (Rubisco), the key enzyme in the Carvin cycle. This is the molecule created by adding CO₂ to the 2-carbon atom of ribulose 1,5-bisphosphate. The winners were Bill Gunn closely followed by the first correct answer from an undergraduate, Ariel Gershon. Ariel is a student at the University of Toronto so it looks like I'm going to have to buy a lunch.

This week's molecule (below) is a sequence. Name the sequence in red and briefly describe it's function.

Email your answer to me at: Monday's Molecule #231. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #240

Last week's molecule (right) [Monday's Molecule #239] was 2-carboxy-D-arabinitol 1-phosphate. It's an inhibitor of the enzyme ribulose 1,5-bisphosphate carboxylase-oxygenase, better known as Rubisco. That's the key enzyme responsible for CO₂ fixation in the Calvin cycle. Plants have to inhibit Rubisco during the night when the lack of sunlight prevents production of ATP and NADPH by photosynthesis. One of the ways they inhibit the enzyme is to produce 2-carboxy-D-arabinitol 1-phosphate at night. The winner is Piotr Gąsiorowski.

This week's molecule (below) is pretty complicated. I don't expect a complete name; just concentrate on getting the correct name of the core part of the molecule on the left. In addition to identifying the molecule, you need to explain what it is used for and, specifically, the purpose of the -N₃ group in the lower left corner of the molecule.

Email your answer to me at: Monday's Molecule #239. The first one with the correct answer wins. I will only post the names of winners 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.)

Monday's Molecule #210

Last week's molecule was the "go" conformation of the leader sequence in the E. coli trp operon. The winners were Rosie Redfield and Quyen Huynh. [Monday's Molecule #209].

Today's molecule isn't very complicated but it has a big effect. You need to be very specific in identifying the exact molecule shown in the figure. I won't accept answers that are ambiguous.

Email your answers to me at: Monday's Molecule #210. 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.)

Monday's Molecule #77

 
Today's molecule is related to a previous Monday's Molecule. This time you have to name the molecule and identify the various symbols on the cartoon. Be as specific as possible.

There's a direct connection between today's molecule and a Nobel Prize. The prize was awarded for figuring out how this molecule was made. It was one of the most brilliant discoveries of the 20th century.

The first person to correctly identify the molecule (and its parts) and name the Nobel Laureate(s), wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first collected the prize. There are five ineligible candidates for this week's reward. You know who you are.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow. I may select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: The molecule is immunoglobulin G (IgG)—same as last week. The V, D, and J symbols stand for variable, diversity, and joining regions of the protein. The antigen binding site is formed from the combination of these regions on the heavy (H) chain and the light (L) chain of the molecule. The ability of antibodies to recognize a huge number of different antigens is due to formation of a huge number of different antigen-binding sites. This is achieved by rearranging the genome in order to bring together one of hundreds of V regions with 20 or so D regions and 5-6 J regions. The recombination events are associated with mutations that serve to create even more diversity.

The generation of antibody diversity by genomic rearrangement was discovered by Susumu Tonegawa who received the Nobel PRize in 1987. Today's winner is Alex Ling or the University of Toronto.

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Monday's Molecule #71

 
Today is Tuesday so it must be time for Monday's Molecule. (Oops! I was traveling yesterday and didn't get around to posting. It doesn't matter since today is a much more important day anyway—it's my birthday.)

Today's molecule is essential for all life as we know it. You need to identify the molecule and give its correct common name as well as the formal IUPAC name. Pay attention to the correct common name—some trivial names just won't do.

There's an indirect connection between today's molecule and a Nobel Prize. The prize I have in mind was not awarded for working out the structure of the molecule. We've already covered that prize. Instead, the prize was for learning something very important about the pathway for synthesis of the molecule. Something genetic.

The first person to correctly identify the molecule and name the Nobel Laureate(s) wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first collected the prize. There are three ineligible candidates for this week's reward.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureates. Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings.

Correct responses will be posted tomorrow. I may select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: The molecule is pyridoxine (3- hydroxy-4,5 -bis (hydroxymethyl) -2-methylpyridine) also known as vitamin B₆. (Pyridoxal and pyridoxamine, along with pyridoxine, make up the members of the B₆ family.)

The Nobel Laureates are George Beadle and Edward Tatum who discovered that mutations in Neurospora affected single enzymes in a pathway. Mutants that were unable to grow on vitamin B₆ were among the first mutants they isolated in the 1940's.

The winner this week is Bill Chaney from the University of Nebraska.

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Monday's Molecule #232

Monday's Molecule #231 [Monday's Molecule #231] was the Shine-Delgarno sequence found a few nucleotides upstream of the initiation codon in many bacterial mRNAs. It interacts (base pairs) with a sequence on the 3′ end of 16S RNA to help form the translation initiation complex. This means that bacteria can have polycistronic mRNAs (from operons) and internal translation initiation. The winners were Keith Conover and Nevraj Kejiou. That's two weeks in a row that an undergraduate from the University of Toronto has won. I will be taking them to lunch. I encourage undergraduates from far, far away to hurry up and send in an answer to this week's molecule!

This week's molecule (left) is covalently bound to the lysine side chain of a protein. It exists in two distinct configurations that can be interconverted by a well-known chemical reaction. Name the two different configurations (common names only) and explain the significance of the reaction.

Email your answer to me at: Monday's Molecule #232. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #228

Last week's molecule was arachidonate, one of the key intermediates in the synthesis of complex lipids, especially protaglandins in mammals [Monday's Molecule #227 ]. The winner is Bill Gunn.

This week's molecule (left) is an easy one for all of the undergraduates who are just beginning a new term. This is one of those molecules that everyone should recognize. Just be sure you pay attention to all the groups and the part in red. All you have to do is supply the common name and NOT the IUPAC systematic name that correctly identifies the exact molecule shown in the image. However, if anyone wants to supply the systematic name, feel free to do so.

Email your answer to me at: Monday's Molecule #228. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #226

Last week's molecule was sucrose 6-phosphate or α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside 6-phosphate [Monday's Molecule #225 ]. The winner is Jean-Marc Neuhaus (again). He appears to be the only Sandwalk reader who has a copy of my book!

Today's molecule (below) looks a bit strange. It should be obvious that this is not a "natural" molecule. What is it and what does it do? You don't need to give me a long systematic name. The common name will do quite nicely.

Email your answer to me at: Monday's Molecule #226. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #218

Last week's molecule was α-tocopherol or vitamin E. You do not need vitamin E supplements and they may even be harmful. Lots of people got it right. The winner was Susan Heaphy [Monday's Molecule #217].

This is the week of Nobel Prize announcements so I've chosen an appropriate molecule. It is very complicated. So complicated, in fact, that there was a Nobel Prize for solving its structure. Name the molecule, the winner of the Nobel Prize, and the year it was awarded. You must get all three answers correct.

Email your answers to me at: Monday's Molecule #218. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #235

Last week's molecule [Monday's Molecule #234] was insect juvenile hormone. The winners are Frank Schmidt and Raul Félix de Sousa (still an undergraduate?). They live in foreign countries so they won't be coming to lunch.

This week's molecule (right) is very common. You have to identify the entire molecule including the specific polynucleotide. Emphasis is on the word "specific"—there's only one possibility. I'm betting that there won't be very many correct answers for this one.

Email your answer to me at: Monday's Molecule #235. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #223

Last week's molecule was a Holliday junction, one of the key intermediates in recombination. It's named after Robin Holliday who has since retired from science to concentrate on being a sculptor. He has produced several "biological" sculptures including "DNA Structure" (top) and "Cross Over" (bottom). The winner is Caroline Josefsson from British Columbia. The undergraduate winner is Andrew Wallace but since he lives in Australia, I suspect he won't be coming to lunch [Monday's Molecule #222].

Today's molecule (below) is not one of my favorite molecules for many reasons. However, it's pretty important in some species. Name the molecule, being as specific as you can without resorting to IUPAC rules. I need the most common name as well as a more detailed name.

Email your answer to me at: Monday's Molecule #223. I'll hold off posting your answers for at least 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #213

Last week's molecule was 6-phosphogluconolactone, the first intermediate in the pentose phosphate pathway. The winner was Brian Shewchuck [Monday's Molecule #212].

Today (Wednesday, but who's counting?) we're going to continue with basic metabolism in honor of all students who are just being introduced to the wonders of introductory biochemistry. Give the common name and identify the pathway. Explain briefly why this pathway is important.

Email your answers to me at: Monday's Molecule #213. I'll hold off posting your answers for 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #212

Last week's molecule was a thymine dimer. The winners were Alex Ling and Matt McFarlane. [Monday's Molecule #211].

Today's molecule is an important part of a major pathway. Give the common name and identify the pathway. Explain briefly why this pathway is important.

Email your answers to me at: Monday's Molecule #212. I'll hold off posting your answers for 24 hours. The first one with the correct answer wins. I will only post the names of people with 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.)

Monday's Molecule #239

Last week's molecules (right) [Monday's Molecule #238] were correctly identified by Dean Bruce (again) who wrote ...

... it is 3-hydroxy-3-methylglutarate-CoA (HMG-CoA) synthetase. HMG-CoA appears to be the only molecule in the active sites of the illustration. Acetoacetyl-CoA and Acetyl-CoA in a Claisen condensation (of the beta-carbonyl of acetoacetyl-CoA) form HMG-CoA.

The mitochondrial one is the isoform involved in metabolic pathology. The disease is called "mitochondrial HMG-CoA synthetase-2 deficiency" in the Online Mendelian Inheritance of Man.

This week's molecule is an important regulatory molecule in some species. Identify it using the standard IUPAC nomenclature and describe the enzyme whose activity it regulates.

Email your answer to me at: Monday's Molecule #239. The first one with the correct answer wins. I will only post the names of winners 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.)

Monday's Molecule #142: Winner

 
The diagram should remind you of the cell cycle and the 2001 Nobel Prize in Physiology and Medicine. Since I already covered Tim Hunt and Paul Nurse, this must be about Lee Hartwell. That means the molecule must be "start" or CDC28.

The winner is Bill Chaney of the University of Nebraska. He has agreed to donate his free lunch to an undergraduate. Unfortunately, there weren't any undergraduate who got the right answer this week so I still have three free lunches to give away.

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Sometimes it's almost impossible to find an image of a specific molecule that honors a Nobel Laureate. This is one of those times.

The diagram provides all the clues necessary to identify an important process and then to identify a particular molecule associated with this week's Nobel Laureate.

You must name the molecule and the Nobel Laureate. Be careful 'cause it's easy to make a mistake and name someone who has already been the subject of a Monday's Molecule.

The first person to identify the molecule and name the Nobel Laureate(s) wins a free lunch. Previous winners are ineligible for six weeks from the time they first won the prize.

There are only six ineligible candidates for this week's reward: Frank Schmidt of the University of Missouri, Joshua Johnson of Victoria University in Australia, Markus-Frederik Bohn of the Lehrstuhl für Biotechnik in Erlangen, Germany, Jason Oakley a biochemistry student at the University of Toronto, Dima Klenchin of the University of Wisconsin, Madison and Alex Ling of the University of Toronto.

Joshua and Dima have agreed to donate their free lunch to an undergraduate. Consequently, I have two extra free lunches for deserving undergraduates so I'm going to award an additional prize to the first undergraduate student who can accept it. Please indicate in your email message whether you are an undergraduate and whether you can make it for lunch. If you can't make it for lunch then please consider donating it to someone who can in the next round.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule(s) and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Prizes so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow.

Comments will be blocked for 24 hours. Comments are now open.

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Monday's Molecule #72

 
Today is Victoria Day in Canada so it must be Monday—time for Monday's Molecule.


Today's molecule is essential for all life as we know it, but biochemists didn't even know it existed 'till after World War II. It's discovery was hailed as one of the greatest contributions to modern biochemistry when the Nobel Prize was awarded for working out its structure and the role it plays in metabolism.

You need to identify the molecule and give its correct common name. We don't need the formal IUPAC name in this case. Pay attention to the correct common name—some incorrect trivial names just won't do.

There's an direct connection between today's molecule and a Nobel Prize. The first person to correctly identify the molecule and name the Nobel Laureate(s) wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first collected the prize. There are three ineligible candidates for this week's reward.

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings.

Correct responses will be posted tomorrow. I may select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

UPDATE: We have a winner! The molecule is uridine diphosphate glucose (UDP-glucose), one of several nucleotide-sugar coenzymes. The Nobel Laureate is Luis Leloir (1970). Several people got the right answer this week—either the quiz was too easy or lots of people have more free time now that undergraduate classes are ending! The first person to email the correct answer was Brian Rosenberg from Harvard University in Boston (Cambridge) (USA). Brian has been invited to a free lunch.

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Monday's Molecule #108: Winner

 
UPDATE: This week's molecule is the genome of ΦX174, a small bacterial virus. It was the first complete genome to be sequenced (Smith et al., 1977, Sanger et al., 1978, Sanger et al., 1978). The sequencing was done in Fred Sanger's lab and Sanger was awarded the Noble Prize a few year later for developing the dideoxy sequencing technology [The Sanger Method of DNA Sequencing].

ΦX174 is interesting because it has overlapping genes—a feature that we now know to be uncommon.

One of the authors on the papers was Michael Smith. He spent a year in Sanger's lab on sabbatical. In 1978 Smith used the ΦX174 sequence in his experiments to develop site-directed mutagenesis (Hutchison et al. 1978). Smith got the Nobel Prize in 1993. He is this week's Nobel Laureate.

This week's winner is James Fraser of the University of California, Berkeley. We will be meeting for lunch in a few months.

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Hutchison, C.A. 3rd, Phillips, S., Edgell, M.H., Gillam, S., Jahnke, P., and Smith, M. (1978) Mutagenesis at a specific position in a DNA sequence. J. Biol. Chem. 253:6551-6560.

Sanger, F., Air, G.M., Barrell, B.G., Brown, N.L., Coulson, A.R., Fiddes, C.A., Hutchison, C.A., Slocombe, P.M., and Smith, M. (1977) The nucleotide sequence of bacteriophage phiX174. Nature 265:687-695.

Sanger, F., Coulson, A.R., Friedmann, T., Air, G.M., Barrell, B.G., Brown, N.L., Fiddes, J.C., Hutchison, C.A. 3rd, Slocombe, P.M., and Smith, M. (1978) The nucleotide sequence of bacteriophage phiX174. J. Mol. Biol. 125:225-246.

Smith, M., Brown, N.L., Air, G.M., Barrell, B.G., Coulson, A.R., Hutchison, C.A. 3rd, and Sanger, F. (1977) DNA sequence at the C termini of the overlapping genes A and B in bacteriophage phi X174. Nature 265:702-705.

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Today's Monday's Molecule really is a molecule. Your task is to identify the molecule from the cartoon shown here. It won't be sufficient to just find the name of the molecule, you will also have to identify the significance behind determining its chemical structure.

There's one scientist who was involved in that determination who also did some important work based, in part, on knowing the sequence. This scientist was awarded a Nobel Prize for his work but the prize didn't come until 15 years later. Name this Nobel Laureate.

The first person to identify the molecule and the Nobel Laureate wins a free lunch at the Faculty Club. Previous winners are ineligible for one month from the time they first won the prize.

There are eight ineligible candidates for this week's reward: Ramon, address unknown, Jason Oakley of the University of Toronto, John Bothwell from the Marine Biological Association of the UK, in Plymouth (UK), Wesley Butt of the University of Toronto, David Schuller of Cornell University, Nova Syed of the University of Toronto, Dima Klenchin of the University of Wisconsin and undergraduate Alex Ling of the University of Toronto

John, David, and Dima have offered to donate their free lunch to a deserving undergraduate so I'm going to continue to award an additional free lunch to the first undergraduate student who can accept a free lunch. Please indicate in your email message whether you are an undergraduate and whether you came make it for your free lunch (with a friend).

THEME:

Nobel Laureates
Send your guess to Sandwalk (sandwalk (at) bioinfo.med.utoronto.ca) and I'll pick the first email message that correctly identifies the molecule and names the Nobel Laureate(s). Note that I'm not going to repeat Nobel Laureate(s) so you might want to check the list of previous Sandwalk postings by clicking on the link in the theme box.

Correct responses will be posted tomorrow. I reserve the right to select multiple winners if several people get it right.

Comments will be blocked for 24 hours. Comments are now open.

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Monday's Molecule #187

Last week's molecule was the core nucleosome complex [Monday's Molecule #186] and nobody who was eligible for a win got it! That's quite shocking. Here's an easy one for today.

Name this molecule, including the name of the "R" group. You'll have to guess but there's really only one possibility in living cells. Don't forget, I need the full name of the most likely molecule given the partial structure that you see.

Post your answer as a comment. I'll hold off releasing any comments 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 comment.)

Monday's Molecule #196

Last week's molecule was tetrahydrofolate, an essential cofactor in several reactions; notably the synthesis of thymidine. The winner was Jacob Troth [Monday's Molecule #195]. He should contact me by email.

This week's molecule is a very important molecule. I'm showing you two different conformations of the same molecule. You need to identify this molecule using its full and complete common name. I'm going to be strict about this, if you give me an ambiguous name you will not win.

Post your answer as a comment. I'll hold off releasing any comments 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 comment.)