Sandwalk: Monday's Molecule #154

Monday, December 19, 2011

Monday's Molecule #154

Today's molecule is a bit more complicated than some of the others. You have to identify the molecule (common name only) and describe (briefly) its function. Can you name the precursor?

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

6 comments :

Joseph C. Somody said...: Thyrotropin-releasing hormone (TRH), also called thyrotropin-releasing factor (TRF), thyroliberin or protirelin

a tropic tripeptide hormone that stimulates the release of thyroid-stimulating hormone and prolactin by the anterior pituitary.; Monday, December 19, 2011 11:33:00 AM
Christopher Yau said...: The molecule is thyrotropin-releasing hormone.

It's a hormone that stimulates the release of thyrotropin or thyroid-stimulating hormone in the pituitary gland.

The hormone precursor is synthesized as a polypeptide chain containing multiple copies of the peptide -Glu-His-Pro-Gly-, which is cleaved to form mature TRH.; Monday, December 19, 2011 12:19:00 PM
Raul A. Félix de Sousa said...: Molecule # 154 is the Thyrotropin Releasing Hormone (TRH), or pyroglutamyl-histidyl-prolinamide (pGlu-H-Pro-NH2). It binds to a receptor of the anterior pituitary causing it to release TSH (Thyrotropic Stimulating Hormone).; Monday, December 19, 2011 1:00:00 PM
Dima Klenchin said...: That's thyrotropin-releasing hormone AKA protirelin. That's a good one because it is linked to a Nobel prize in medicine (1977).
The function is kind of obvious from the name - it stimulates secretion of thyrotropin.

It is basically a EHP peptide with Glu condensing on itself. So the immediate precursor has to be simply EHP.; Monday, December 19, 2011 1:38:00 PM
jimmy neutron said...: Hmm, it appears to be thyrotropin releasing hormone. It is released by the hypothalamus into the hypophyseal portal system. I do not know what the precursor is exactly. Its function is stimulating the release of thyroid stimulating hormone and prolactin from the anterior pituitary.

If I'm right, it would be due to my intense review for the MCAT.

Roger Fan
Undergrad; Monday, December 19, 2011 1:55:00 PM
Matt G said...: It is TRH, thyrotropin releasing hormone. It is secreted from the hypothalamus and interacts with TRHR in the anterior pituitary, causing the release of TSH, thyroid stimulating hormone.; Monday, December 19, 2011 2:47:00 PM

Quotations

The old argument of design in nature, as given by Paley, which formerly seemed to me to be so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings and in the action of natural selection, than in the course which the wind blows.Charles Darwin (c1880)

Although I am fully convinced of the truth of the views given in this volume, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory.

Charles Darwin (1859)

Science reveals where religion conceals. Where religion purports to explain, it actually resorts to tautology. To assert that "God did it" is no more than an admission of ignorance dressed deceitfully as an explanation...

Peter Atkins

Quotations

The world is not inhabited exclusively by fools, and when a subject arouses intense interest, as this one has, something other than semantics is usually at stake. Stephen Jay Gould (1982)
I have championed contingency, and will continue to do so, because its large realm and legitimate claims have been so poorly attended by evolutionary scientists who cannot discern the beat of this different drummer while their brains and ears remain tuned to only the sounds of general theory. Stephen Jay Gould (2002) p.1339
The essence of Darwinism lies in its claim that natural selection creates the fit. Variation is ubiquitous and random in direction. It supplies raw material only. Natural selection directs the course of evolutionary change. Stephen Jay Gould (1977)
Rudyard Kipling asked how the leopard got its spots, the rhino its wrinkled skin. He called his answers "just-so stories." When evolutionists try to explain form and behavior, they also tell just-so stories—and the agent is natural selection. Virtuosity in invention replaces testability as the criterion for acceptance. Stephen Jay Gould (1980)
Since 'change of gene frequencies in populations' is the 'official' definition of evolution, randomness has transgressed Darwin's border and asserted itself as an agent of evolutionary change. Stephen Jay Gould (1983) p.335
The first commandment for all versions of NOMA might be summarized by stating: "Thou shalt not mix the magisteria by claiming that God directly ordains important events in the history of nature by special interference knowable only through revelation and not accessible to science." In common parlance, we refer to such special interference as "miracle"—operationally defined as a unique and temporary suspension of natural law to reorder the facts of nature by divine fiat. Stephen Jay Gould (1999) p.84

Quotations

My own view is that conclusions about the evolution of human behavior should be based on research at least as rigorous as that used in studying nonhuman animals. And if you read the animal behavior journals, you'll see that this requirement sets the bar pretty high, so that many assertions about evolutionary psychology sink without a trace.

Jerry Coyne
Why Evolution Is True

I once made the remark that two things disappeared in 1990: one was communism, the other was biochemistry and that only one of them should be allowed to come back.

Sydney Brenner
TIBS Dec. 2000

It is naïve to think that if a species' environment changes the species must adapt or else become extinct.... Just as a changed environment need not set in motion selection for new adaptations, new adaptations may evolve in an unchanging environment if new mutations arise that are superior to any pre-existing variations

Douglas Futuyma

One of the most frightening things in the Western world, and in this country in particular, is the number of people who believe in things that are scientifically false. If someone tells me that the earth is less than 10,000 years old, in my opinion he should see a psychiatrist.

Francis Crick

There will be no difficulty in computers being adapted to biology. There will be luddites. But they will be buried.

Sydney Brenner

An atheist before Darwin could have said, following Hume: 'I have no explanation for complex biological design. All I know is that God isn't a good explanation, so we must wait and hope that somebody comes up with a better one.' I can't help feeling that such a position, though logically sound, would have left one feeling pretty unsatisfied, and that although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist

Richard Dawkins

Another curious aspect of the theory of evolution is that everybody thinks he understand it. I mean philosophers, social scientists, and so on. While in fact very few people understand it, actually as it stands, even as it stood when Darwin expressed it, and even less as we now may be able to understand it in biology.

Jacques Monod

The false view of evolution as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing programs that model evolution by natural selection.

Richard Lewontin

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Monday, December 19, 2011

Monday's Molecule #154

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