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Monday, April 28, 2008

Should Undergraduate Programs Be Easier?

 
We have a biochemistry program for undergraduates. It would be called a major at most universities but at the University of Toronto we call it a Biochemistry Specialist Program. Here's an outline with the number of credits, where (1) is a standard two-semester course ...

1st year
Calculus (1), Biology (1), Physics (1), Chemistry (1)

2nd year
Biochemistry (1), Organic Chemistry (0.5), Physical Chemistry (0.5), Cell & Molecular Biology (1)

3rd year
Biochemistry Laboratory (0.5), Proteins (0.5), Nucleic Acids (0.5), Molecular Biology (1), 1.5 extra credits from a list of science courses

4th year
Advanced Biochemistry Laboratory (1), four (0.5) credit courses from a list of biochemistry and molecular biology courses

Here's the problem. Enrolment in this program is dropping because the students perceive it as being too hard. A number of easier, less rigorous, programs have recently become available in other departments. These other programs are being promoted as excellent choices for an undergraduate degree. Students are being told that these easy program will be just as acceptable as the more difficult ones when they apply to graduate school. (That won't be true in our department.)

Students believe that they will get higher grades in these other programs and that will make it easier to get into medical school or graduate school.

What should we do? There's a possibility that our program will disappear if we do nothing. On the other hand, making it a lot easier by dumbing down the material and giving higher grades goes against the principles that many of us believe in.

Have any other schools faced this situation? What did you do? What do the students think?



Who Do You Know?

 
The Friendly Atheist asks ...
Who is the most famous person you know (who would admit to knowing you back)?
You can see my answer over there. Sandwalk readers might like to jump in and drop a few names.


Monday's Molecule #69

 
This colorful molecule plays an important role in regulating carbohydrate metabolism, among other things. Your task for today is to identify the molecule. Be as specific as possible (what species?).

Identify the Nobel Laureate(s) who was/were awarded a Nobel Prize for discovering fundamental properties of this molecule without knowing the sequence or the structure. [Hint: The award was very controversial in the home country of the Nobel Laureate(s).]

Here's part of the PDB file to help you.

SEQRES 1 A 191 PHE PRO THR ILE PRO LEU SER ARG LEU PHE GLN ASN ALA
SEQRES 2 A 191 MET LEU ARG ALA HIS ARG LEU HIS GLN LEU ALA PHE ASP
SEQRES 3 A 191 THR TYR GLU GLU PHE GLU GLU ALA TYR ILE PRO LYS GLU
SEQRES 4 A 191 GLN LYS TYR SER PHE LEU GLN ALA PRO GLN ALA SER LEU
SEQRES 5 A 191 CYS PHE SER GLU SER ILE PRO THR PRO SER ASN ARG GLU
SEQRES 6 A 191 GLN ALA GLN GLN LYS SER ASN LEU GLN LEU LEU ARG ILE
SEQRES 7 A 191 SER LEU LEU LEU ILE GLN SER TRP LEU GLU PRO VAL GLY
SEQRES 8 A 191 PHE LEU ARG SER VAL PHE ALA ASN SER LEU VAL TYR GLY
SEQRES 9 A 191 ALA SER ASP SER ASP VAL TYR ASP LEU LEU LYS ASP LEU
SEQRES 10 A 191 GLU GLU GLY ILE GLN THR LEU MET GLY ARG LEU GLU ASP
SEQRES 11 A 191 GLY SER PRO ARG THR GLY GLN ALA PHE LYS GLN THR TYR
SEQRES 12 A 191 ALA LYS PHE ASP ALA ASN SER HIS ASN ASP ASP ALA LEU
SEQRES 13 A 191 LEU LYS ASN TYR GLY LEU LEU TYR CYS PHE ARG LYS ASP
SEQRES 14 A 191 MET ASP LYS VAL GLU THR PHE LEU ARG ILE VAL GLN CYS
SEQRES 15 A 191 ARG SER VAL GLU GLY SER CYS GLY PHE
The first person to correctly identify the specific 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 is only one 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 Laureates so you might want to check the list of previous Sandwalk postings.

Correct responses will be posted tomorrow along with the time that the message was received on my server. I may select multiple winners if several people get it right.

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

UPDATE: This week's winner is David Schuller of Cornell University (again). He correctly identified the molecule as human growth hormone and the Nobel Laureate is Bernardo Houssay (1947). Thanks to all the others who sent in their guesses.


Sunday, April 27, 2008

Gene Genie #30

 

The 30th edition of Gene Genie has been posted at Gene Expression [Gene Genie #30].
Welcome to the 30th Gene Genie!
The beautiful logo was created by Ricardo at My Biotech Life.

The purpose of this carnival is to highlight the genetics of one particular species, Homo sapiens.

Here are all the previous editions .....
  1. Scienceroll
  2. Sciencesque
  3. Genetics and Health
  4. Sandwalk
  5. Neurophilosophy
  6. Scienceroll
  7. Gene Sherpa
  8. Eye on DNA
  9. DNA Direct Talk
  10. Genomicron
  11. Med Journal Watch
  12. My Biotech Life
  13. The Genetic Genealogist
  14. MicrobiologyBytes
  15. Cancer Genetics
  16. Neurophilosophy
  17. The Gene Sherpa
  18. Eye on DNA
  19. Scienceroll
  20. Bitesize Bio
  21. BabyLab
  22. Sandwalk
  23. Scienceroll
  24. biomarker-driven mental health 2.0
  25. The Gene Sherpa
  26. Sciencebase
  27. DNA Direct Talk
  28. Greg Laden’s Blog
  29. My Biotech Life
  30. Gene Expression

Does science make belief in God obsolete?

 
The John Templeton Foundation has a website where "leading scientists and scholars" discuss the question "Does science make belief in God obsolete?" [A Templeton Conversation] One of these prominent intellectuals is Ken Miller and his answer is "Of course not."

One of our regular readers (Oldcola) left a comment on this site where he criticized the views of Ken Miller. His comment was initially posted intact but within a few days a heavily edited version replaced the original comment. The man responsible for editing the comment is Gary Rosen.

Apparently, the Templeton Foundation objected to the claim that they were soft on creationism, according to Oldcola. Oldcola requested that his edited comment be removed, and it was.

You can read an extended critique of Ken Miller's position on Oldcola's blog Coffee and Sci(ence) [Does science make belief in God obsolete?]. It's an excellent essay.

Incidentally, although it's not directly relevant to Miller's position, and it's not something that he clearly states, I find that theists of all sorts make the same false assumption when discussing the conflict between science and religion. They almost always assume that their atheist friends started life as theists and then lost their faith. Thus, they assume that there is something about science that disproves the default assumption; namely, that God exists.

While this might be true of many atheists, especially in the USA, it's not true of many others in Europe and elsewhere. Many atheists never bought into a belief in supernatural beings in the first place. This will be more and more likely as time goes on and the children of atheists have children of their own. When scientists like Ken Miller have to explain why science makes them go from being an atheist to a beleiver, it becomes much more difficult. Just look at the contortions that Francis Collins had to come up with.

Here's the point. It's up to theists to start making the case for the existence of God instead of just whining about those who have lost their faith. Let's say you've been raised in a home where superstitious beliefs are not valued. Then you start studying science seriously when you get to university. Is there anything about science that points to the existence of supernatural beings given that you haven't been brainwashed to believe in them as a child? I don't think so.

As Oldcola points out, many theists are simply afraid to abandon their comforting delusions. They believe science teaches us that the universe has no purpose—they are correct—and for them this depressing thought is sufficient to prove that science must be wrong. What they fail to understand is that the thought is only "depressing" if you've been brainwashed to to believe that there is a purpose in the first place.


Is Anyone Stupid Enough to Fall for This?

 
I received this message today ...
Dear UTORONTO.CA Email Account Owner,

This message is from UTORONTO.CA messaging center1 to all UTORONTO.CA email account owners. We are currently upgrading our data base and e-mail account center. We are deleting all unused UTORONTO.CA email account to create more space for new accounts.

To prevent your account from closing you will have to update it below so that we will know that it's a present used account.

CONFIRM YOUR EMAIL IDENTITY BELOW

Email Username :

EMAIL Password :

Address :

Department :

Attention!!! Account owner that refuses to update his or her account within ten days of receiving this Notification will lose his or her account permanently.

Thank you for using UTORONTO.CA!

Notification Code:VX2G99AAJ

Sandra Jacobson
ONLINE SERVICES
My question is serious. Is there any data out there to suggest that scams2 like this actually succeed? Are there people who respond to these notices by sending off their email passwords?

Also, what's the purpose behind this attempt to get email passwords? What do they plan to do with them? Are they hoping that the email passwords will give them access to the user accounts or do they just like to read email messages?



1. The sender is "Online Services (onlineservices@utoronto.edu)." A domain that does not exist. The reply-to address is "dataguards@instructor.net." I've often wondered how these scams work. How do the perps get the replies if the return address is bogus?

2. It's easier to recognize that this is a bogus message because of the language—obviously not written by someone whose native language is English—but even if it was grammatically correct most people would know that it's a scam, right?

Saturday, April 26, 2008

Darwin's Garden

 
In order to walk on the sandwalk you have to pass through Darwin's garden behind Down House. Most visitors take advantage of the opportunity to pass through the greenhouses and the potting shed as well. Darwin was a passionate gardener and he did many experiments with plants. Some of his original varieties are still growing in the garden.

The New York Botanical Garden has mounted an exhibit of Darwin's experiments on plants [What Darwin Saw Out Back]. I'll have to see if Mrs. Sandwalk wants to take a trip to New York to see it with me.


[Hat Tip: Don Henry]

Ben Stein Meets Charles Darwin

 
Do you remember this image from the Expelled trailer? [Expelled: The Movie] It's a picture of Ben Stein looking at the statue of Charles Darwin in the cafeteria of the Natural History Museum in London (UK).

The group over at the The Beagle Project ran a contest to come up with a funny caption for the photo and the result has just been announced [Caption (absolutely no) contest!]. It's excellent—very close to what I would have said if I had the wit and talent to enter the contest.
A fortnight ago we launched a caption contest for the provocative image below, originally taken from Time's negative review of Expelled. We received twenty-six highly humorous entries, but there was one that towered, marble head and shoulders, above the rest, both for its comic value and also for the amount of work involved in realising it.
I'm not going to give away the answer because you all need to scoot on over to The Beagle Project log and donate some money while you're there.


Fibrin and Blood Clots

 
The formation of blood clots in mammals is an example of a complex pathway that does not seem to be very well "designed." This hasn't stopped the intelligent design creationists who often use it as an example of irreducible complexity. They conclude that the clotting pathway cannot possibly have evolved.

Last year I posted a bunch of articles on blood clotting because I needed to learn about it myself. Since then I've kept an eye on the literature but I've been too lazy to write up all the new information that comes out on a regular basis. Fortunately, André Brown has come to the rescue. He published a paper on the elastic properties of fibrinogen last year (Brown et al. 2007) and now he reviews a recent paper by his collaborator, John Weisel, that has just come out in Science. André's blog is Biocurious, a blog about biology written by two physics graduate students. The post url is New Perspective on Blood Clot Mechanics.

Theme

Blood Clotting
The image above shows blue strands of fibrin trapping red blood cells (red) and platelets (pink) to form a clot. It is from Yuri Veklich and John W. Weisel, University of Pennsylvania School of Medicine [Building better clots]. The structure of fibrinogen (below) hints at the complexity. Follow the link in the "Theme Box" to learn more.



Brown, A.E.X., Litvinov, R.I. Discher, D.E. and Weisel, J.W. (2007) Forced Unfolding of Coiled-Coils in Fibrinogen by Single-Molecule AFM. Biophys J. 92: L39–L41. [doi: 10.1529/biophysj.106.101261]

Friday, April 25, 2008

Fun with Polls

 
The Expelled website has a poll asking "Do you think the theory of Intelligent Design should be taught in our education system?"

When PZ Myers discovered it, the "yes" voters were ahead three to one. Now that the Pharyngula readers have voted [Crash this poll], the results are very different. Eat your heat out Ben Stein!!


Do We Need Genetic Counselors?

 
The blogs promoting genetic testing usually think that we don't need genetic counselors to interpret the results and advise on what to do. For the most part, they seem happy to leave it up to the individual to decide on a course of action if they discover they have a particular genetic trait. I don't agree. I think this is much more complicated and I'm pretty skeptical about the motives of the private, personal genetics, for-profit, companies.

The Sciphu Weblog has an interesting posting on this issue [Now this is why we need genetic counselors]. It's worth reading.


Top 100 Public Intellectuals

 
The Foreign Policy website has a list of the top 100 public intellectuals from around the world [The Top 100 Public Intellectuals: Bios].

The Canadians are: Malcolm Gladwell, Michael Ignatieff, Steven Pinker, and Charles Taylor. I would have included Irshad Manji, Bob Rae, and Don Cherry.

I included Don Cherry because he would fit right in with David Petraeus who is listed as a top 100 public intellectual.

There are several scientists and people who write about science and religion: Pope Benedict XVI, Noam Chomsky, Richard Dawkins, Daniel Dennett, Jared Diamond, Christopher Hitchens, James Lovelock, Lee Smolin, Harold Varmus, J. Craig Venter, E.O. Wilson. It's interesting that Francis Collins and Ken Miller aren't on the list since the main criterion for inclusion seems to be that the person has written a book and they have Miller & Collins have both written books.

I would have included Richard Lewontin, Bruce Alberts, and David Suzuki. Are there any others who should be on the list? Who should be deleted to make room?


[Hat Tip: Sean at Cosmic Variance]

Wednesday, April 23, 2008

Writing with Amino Acids

 
Eva has a picture of a bracelet that spells out "I am starstuff" using the structures of several amino acids and their single-letter identifier. Some of you may be wondering exactly how that phrase is written since there seems to be an unusual letter in there. Check out Etsy Wednesday - I Am Starstuff for the answer.


Nobel Laureate: Lord Alexander Todd

 

The Nobel Prize in Chemistry 1957.

"for his work on nucleotides and nucleotide co-enzymes"

Lord Alexander Todd (1907 - 1997) was awarded the 1957 Nobel Prize in Chemistry for his work on the the chemical structure of nucleotides and nucleic acids, particularly the phosphate derivatives. Todd is best known for working out the linkage between nucleotides in RNA and DNA but he is also responsible for proving that the sugar moieties are particular ring structures called β-D-ribofuranosides and β-D-deoxyribofuranosides [Monday's Molecule #68]. His lab in Cambridge (UK) synthesized all of the common nucleotides.

The chemical structure of DNA was known by the time Watson & Crick began working on the three-dimensional structure in 1952.

The presentation speech was delivered by Professor A. Fredga, member of the Nobel Committee for Chemistry of the Royal Swedish Academy of Sciences.THEME: Nobel Laureates
Your Majesties, Your Royal Highnesses, Ladies and Gentlemen.

Nucleotides and nucleotide coenzymes are words that may seem strange and abstruse, but these compounds are of great importance to all of us. We have such substances everywhere in our bodies and they regulate many of the processes of life. The term is derived from nucleus, which here refers to cell-kernels or nuclei. The Nobel Prize of this year has nothing to do with atomic nuclei, nuclear fission or hydrogen bombs. Nucleotides are regularly found in the chromosomes of the cell-kernels, where they are connected with the units of heredity, but also in the cell plasma. In combination with proteins they constitute the virus molecules and many coenzymes are nucleotides of low molecular weight but with a special structure. Thus they are a group of substances of very great biological importance, perhaps the most important of all.

The nucleotides have been known for nearly 90 years and they have been frequently studied by both chemists and biologists, but for a long time they were, from the chemist's point of view, an underdeveloped field of research. The difficulties were too great. Gradually it was established that they are built up of three different kinds of "building-stones" of quite different chemical character: phosphoric acid, a sugar, and a heterocyclic base containing nitrogen. I cannot express it more popularly, except to mention that these bases are compounds related to caffeine. Two different sugars are found, ribose and desoxy-ribose, and about half a dozen different bases. The simple building-stones may then be combined in hundreds or thousands to form macromolecules, the nucleic acids.

It is, however, not enough to know the building-stones; we must also know how they are connected to each other. The building-plan, the pattern or whatever you prefer to call it, must be very essential for the behaviour of the macromolecule in chemical and biological processes. The sugars and the heterocyclic bases are both somewhat complicated molecules, which may be connected to each other in several different ways, and finally it must be established how the phosphoric acid is bound. The task is very difficult; the combination of three quite different kinds of building-stones in one macromolecule gives it a very special character and neither the traditional methods of organic chemistry, nor those of inorganic chemistry are directly applicable. It is, however, pre-eminently a task for an organic chemist, and for more than ten years Sir Alexander Todd has held a leading position in this field.

Some idea of the building-plan may be obtained by examining the products formed by partial degradation of the macromolecule into small fragments containing a limited number of building-stones. Conclusive evidence can, however, only be obtained by synthetic methods, by building up possible combinations of sugars and bases - with or without phosphoric acid and comparing them with the degradation products. It is of course imperative to use such methods that the structure of the synthetic products is irrefutable.

The work has been very comprehensive, and many special methods have been evolved, but it is hardly possible to give a non-chemist a clear idea of the brilliant experimental work accomplished. Perhaps I should specially mention the methods for introducing phosphoric acid, the phosphorylation. In recent years, the fundamental role of phosphoric acid in the biochemical processes has become more and more evident, and the new phosphorylation methods - now approximating to those used in the biosynthetic procedures - are also of interest outside the special domain of nucleotide chemistry.

The building-plan of the nucleic acids is now established, at least in its outlines. We have a long chain, where the links are alternately sugar and phosphoric acid, and to each sugar molecule is attached a heterocyclic base as a small pendant. Thus there is an equal number of acid and basic groups. The different building-stones are always connected according to the same pattern and the difference between various nucleic acids must therefore be due to the kinds of bases and their relative arrangement. The number of different types is small - in a certain chain usually only four different bases occur - but in a macromolecule with thousands of appendant base molecules the number of possible combinations must be very great. We are familiar with the coding potentialities of the Morse alphabet, which has only two symbols, dots and dashes.

Through Sir Alexander's work a solid foundation is laid for the future development in this field. Starting from this work, other scientists have advanced very fascinating theories as to the arrangement of the chains; it seems that they may be coiled up as a helix with the bases inside. This model can perhaps explain how a nucleic acid chain can bring about the formation of another similar chain or even of a protein. We are here approaching very fundamental biological questions.

The synthetic methods have also been successfully applied to the preparation of low-molecular nucleotide coenzymes, for instance the cozymase, which plays a part in alcoholic fermentation and other biochemical processes. The ways are now open for synthetic preparation of the different types occurring in nature. It is also possible to synthesize coenzymes with slightly modified structure and study the effect of these modifications on the activity, and hence gain better insight into the mode of action of the enzymes.

Sir Alexander Todd. Some fifteen years ago you started your work in nucleotide chemistry. You saw the great importance of this topic and you did not underrate the difficulties. Today the chemical structure of these compounds is established - in any case in its outlines - and a solid foundation is laid for future work by biochemists and biologists. Results of utmost interest have already been reported and others will follow.

An organic chemist is perhaps most impressed by your studies in phosphorylation. We know today that phosphoric acid is engaged in most biochemical processes, but we know rather little of how it works. Some years ago, you expressed the opinion that the methods used by the living organism owe their air of magic largely to our lack of knowledge of the simple chemistry of the esters of phosphoric acids. You have learned to handle these esters with amazing skill, and I am sure that in due time the air of magic will disperse.

In recognition of your services to chemistry and to natural science as a whole, the Royal Swedish Academy of Sciences has decided to bestow upon you the Nobel Prize for Chemistry for your work on nucleotides and nucleotide coenzymes. To me has been granted the privilege of conveying to you the most hearty congratulations of the Academy, and of inviting you to receive your prize from the hands of His Majesty the King.



Why Do People Laugh at Creationists?

 
This video asks the question and gives a pretty good answer.




[Hat Tip: Mike's Weekly Skeptic Rant]