Monday, December 31, 2012

Happy New Year

I want to wish to all the readers of World of Biochemistry a 2013 full of profissional and personal success! :)

Sunday, December 16, 2012


Enantiomers are a class of isomers belonging to the optical isomers, taht means, they are characterized by differencies in regions containing at least one chiral carbon.
The enantiomers are considered as the mirror image of one another, like it happens with our hands. Therefore, they are symmetric, non-superimposable molecules.

However, when trying to compare two potential enantiomers, it is not always easy to imagine the rotation of the molecules in space, in order to check whether one is dealing with mirror images of one another. So, the best thing to do is to use the definition of enantiomer. This definition tells us that the enantiomers are molecules that differ in the configuration of ALL chiral carbons. Thus, what should be done is:
1. Identify all the chiral carbons present in the molecule.
2. Verify if the configuration of each one differs or stands in the possible enantiomer.
When I speak in different configuration, I am referring to the situation where it is impossible to overlap all substituents of a chiral carbon in the two molecules. If the configuration of ALL chiral carbons is different, they are enantiomers. If there is at least one chiral carbon with the same configuration in both molecules, they are no longer enantiomers.
Finally, by definition, when there is only one chiral carbon in a molecule, and the corresponding configuration is different in the two isomers, these are enantiomers.

Thursday, December 13, 2012

Music about biochemistry

This song made by Dr. Ahern ( is one of those that everyone likes. It is based on the music If You're Happy and You Know It, Clap Your Hands, and it covers several issues of biochemistry. Come on, everybody singing...:)

If You're Molecular and Know It, Clap Your Hands

Instructor sings regular text, class sings bold text

If you want to have a lot of energy (En-er-gy)
You had better make a lot of ATP (A-T-P)
I will only tell you once
You need proton gradients
And a bunch of starting stuff like ADP (A-D-P)

If you hanker for a sweet thing you can taste (You can taste)
And your Atkins diet book has been misplaced (been misplaced)
You should know adrenalin
Is an aid to getting thin
Putting phosphates onto enzymes trims your waist (trims your waist)

If you're feeling kind of achy in your ways (in your ways)
And that hangover has hung around for days ('round for days)
You should know you silly dear
Pain does not come from your beer
Prostaglandin's made by PGH synthase (H synthase)

There are acids in the bile that make up gall (make up gall)
Which emulsify triacylglyerol (glycerol)
If your health is gone to hell
You should blame the LDLs
'Cause they carry all of that cholesterol (lesterol??)

Some phosphates and a sugar on a base (on a base)
Make up C's and G's and U's or T's and A's (T''s and A's)
You can make a DNA
Or a strand of RNA
If you add a template and polymerase (lymerase??)

If you want to ace this test with utmost ease (utmost ease)
You don't really have to get down on your knees (on your knees)
And you need not say a prayer
So please don't pull out your hair
Just go download QuickTimes or the MP3s (MP3s)

Sunday, December 9, 2012

Famous sentence (16)

Concerning levers:
Give me a place to stand, and I will move the Earth. (Archimedes)

Wednesday, December 5, 2012

Video about the name of a protein

Titin is the biggest protein that exists in our body. It is composed by almost 27000 aminoacid residues and has a molar mass of about 3tons/mol!!! As you can imagine, it should be hard to pronounce its name according tot the rules of organic chemistry numenclature. Here it is a video of someone brave enough to spend more than 3 hours saying the name of this protein, which has "only" 189819 letters. You can even notice that during the video his beard grows. eheheh

Thanks to Hélder Pimenta for this contribution! :)