Wednesday, October 31, 2012

Happy Halloween


Friday, October 26, 2012

Conformational isomers



Today I will post about conformational isomers, a class that belongs to the family of stereoisomers. This type of isomerism is somehow controversial, since there are people that consider it, indeed, as a particular type of isomerism, while others consider that we are talking about different structures of the same molecule.
In order to understand the concept of conformational isomer, it is recommended to highlight a property that is observed only in single bounds – its capacity to rotate, functioning as an axis.
In this context, regions of a molecule that contain single bounds are characterized by their high rotational flexibility.
When two molecules are compared, if it is possible to convert one in the other through rotation on one (or more) single bounds, they are conformational isomers.
Since, in fact, the two molecules are converted without the need to break or create new covalent bonds (this is the definition of conformation, as it was explained here in a previous post…), there are people that claim that those molecules don’t have to be considered isomers.

Saturday, October 20, 2012

Music about codons

This music was bsed on the famous When I'm Sixty Four, and talks about codons. It was made by Dr. Kevin Ahern (www.davincipress.com/metabmelodies.html).

The Codon Song

Building of proteins, you oughta know
Needs amino A's
Peptide bond catalysis in ribosomes
Triplet bases, three letter codes
Mixing and matching nucleotides
Who is keeping score?
Here is the low down
If you count codons
You'll get sixty four

Got - to - line - up - right
16-S R-N-A and
Shine Dalgarno site

You can make peptides, every size
With the proper code
Start codons positioned
In the P site place
Initiator t-RNAs
UGA stops and AUGs go
Who could ask for more?
You know the low down
Count up the codons
There are sixty four

Tuesday, October 16, 2012