Wednesday, January 30, 2013

Metabolic map about cytokines and the inflammatory response

Friday, January 25, 2013

Famous quote (18)

(Martin Luther King, Jr.)

Tuesday, January 22, 2013


Tautomers are a particular class of isomers, which belong to the constitutional isomers. They are molecules characterized by differ among themselves usually in the position of a hydrogen atom. Thus, reactions involving the transfer of a H + to another position in the same molecule (i.e., intramolecular transfer of a proton), are tautomerization reactions.
The tautomers have a high rate of interconversion, and due to this fact often both tautomeric forms are "ignored" and they are considered as the same molecule.
The most common situation is called keto-enol tautomerism. But what does this mean? When we say "keto", we are referring to a molecule which has a carbonyl group, whilst when we say "enol", it is a molecule having one hydroxyl group and the carbon which has this group is simultaneously involved in a double bond. Hence the name enol (en = double bond; ol = hydroxyl group). Normally the form "keto" is the most favored, but in certain (bio)chemical contexts, it may originate the enol form.
In Biochemistry, tautomers have an important role in the metabolism of nitrogen bases, in particular in the pairing between nitrogen bases which occurs in DNA and mainly in RNA.

Saturday, January 19, 2013

Music about biochemistry

This song has, in my opinion, one of the funniest lyrics made by dr. Ahern ( :)
It was based on the music Thank God I'm a Country Boy.

Thank God There's a Video

Students sing text in bold

There's a bundle of things a student oughta know
And Ahern's talk isn't really very slow
Learnin' ain't easy / the lectures kinda blow
Thank God there's a video

Well we've gone through the cycles and their enzymes too
Studying the regulation everything is new
I gotta admit that I haven't got a clue
What am I gonna do?

So I got me a note card and bought me a Stryer
Got the enzymes down and the names he requires
I hope that I can muster up a little more desire
Thank God there's a video

Just got up to speed about the NAD
Protons moving through Complex Vee
Electrons dance in the cytochrome C
Gotta hear the MP3

Fatty acid oxidation makes the acetyl-CoA
Inside the inner matrix of the mitochondri-ay
It's very complicated, I guess I gotta say
Thank God there's a video

So I got me a note card and bought me a Stryer
Got the enzymes down and the names he requires
I hope that I can muster up a little more desire
Thank God there's a video

Replication's kind of easy in a simple kind of way
Copyin' the bases in the plasmid DNAs
Gs goes with Cs and Ts go with As
Thanks to polymerase

And the DNA's a template for the RNA
Helices unwinding at T-A-T-A
Termination happens, then the enzyme goes away
Don't forget the poly-A

So I got me a note card and bought me a Stryer
Got the enzymes down and the names he requires
I think that I can muster up a little more desire
Thank God there's a video


Thursday, January 17, 2013

Famous quote (17)

Look deep into nature, and then you will understand everything better. (Albert Einstein)

Sunday, January 6, 2013


The diastereomers are a class of isomers which, together with the enantiomers, belong to the family of optical isomers. Therefore, they differ in the configuration of chiral carbons. However, in the case of diastereoisomers, the molecules must have at least two chiral carbons which means that whenever there is only one chiral carbon, the molecule do not present diastereoisomers. As I mentioned in a previous post here on the blog, the enantiomers differ in the configuration of ALL chiral carbons. The diastereomers are characterized by presenting AT LEAST ONE chiral carbon with different configuration and AT LEAST ONE chiral carbon with the same configuration.
Therefore, if a molecule with two chiral carbon presents one with the same configuration in both isomers, these are diastereoisomers.
If the molecule has 100 carbons chiral, an enantiomer has to have an opposite configuration at all of them. All the intermediate situations, where at least one configuration remains the same, these are diastereoisomers.
Interestingly, despite the difference between the diastereomers can be in the configuration of only one chiral carbon, they have distinct properties. Please see what happens in the following curious molecules ...
Both have two chiral carbons, one of which has the same configuration and other features different configuration. However, this "small" difference causes one of the diastereoisomers to have a sweet taste (molecule from left), while the other has a bitter taste (right molecule).

Wednesday, January 2, 2013

Music about E. coli

I usually say, in a funny way, that Escherichia coli is one of the biochemists best friends, due to its widely used in the investigation labs. Dr. Ahern ( has decided to dedicate it a song, based on the Christmas music Rudolph the Red-Nosed Reindeer.

The E. coli Song

Instructor sings
E. coli's very simple
That's the way the story goes
But if you worked around it
You would probably hold your nose

Most of the other cell types
Have a mitochondrion
They use to make triphosphates
By phos-phor-y-la-she-un

Everyone sings
When there is no oxygen
Coli's got it made
Glucose breakdown products all
Wind up making ethanol

Instructor sings
Then all the cells around it
Shout E. coli's name with glee
“You make us feel light-headed”
“When you act fermentally”