Let's talk about Amino Acids! The best description of what an amino acids are is that they are the building blocks of polypeptides (or proteins usually). The key properties of amino acids are the following: They all have a chiral center except for glycine, and most of these are "L" (note we're using the L/D system here, not con/dis, S/R, or anything else). Also, AAs are usually zwitterionic in nature. This means that they have a definite and very strong dipole, as can be seen once the link to be put below is up and running. Finally, AAs have side chains which distinguish them from each other (and there are a lot of them, literally thousands of different ones, of which 20 are common in most species). These side chains can be aliphatic non-polar, polar but uncharged, aromatic, or charged positively or negatively.

Now just above we mentioned the number twenty and the words amino acids in the same sentence. That should be a hint that there are twenty biggies, and that's what we're going to look at now. And we're going to look at it in the form of a table, so bear with me.

Non Polar aliphatic R groups:

Glycine, (Gly) alanine, (Ala) valine, (Val) leucine, (Leu) isoleucine, (Ile) and proline (the lone cyclical AA) (Pro)

Polar Uncharged R groups: serine, (Ser) threonine, (Thr) cystein, (Cys) methionine, (Met) asparagine, (Asn) and glutamine (Gln)

Aromatic R groups: phenylalanine, (Phe) tyrosine, (Tyr) and tryptophen (Trp)

Positively charged R groups: lysine, (Lys) argenine, (Arg) and histidine (His)

Negatively charged R groups: asparatate (Asp) and glutamate (Glu)

Now look at those names. You will notice that there is a three letter abbreviation following each name. That abbreviation is important because it is how most AAs are identified when they must be written down (the names are often too long). You should know this code. It helps to realize that most of the codes for the AAs are the first three letters of the name, but be careful of the exceptions. Good luck!

you know what, this will be finished later when I feel like using the scanner more. Enjoy until then.

Make your own free website on Tripod.com