Amino Acids

Today, we discussed the chemical structure of an amino acid, the building blocks (or monomers) that make up proteins (a polymer).  An amino acid looks like this:

Notice the amine group, carboxyl group, and that pesky R-group, the wild card that is different for every amino acid and determines its properties.  There are about 20 different amino acids, all with their own R-group:

That'a a lot!  Notice that some are negatively charged, some are positively charged, some are polar, and some are nonpolar.

We can join amino acids together by dehydration synthesis, also called condensation, which looks like this:

Or, reverse the process and do a hydrolysis reaction, liberating two individual amino acids.

These are the fundamental mechanics of building a polypeptide, or protein; tomorrow, we'll look at protein folding, the dynamic molecular dance that occurs when a long polypeptide chain assumes its complex shape.

Homework

In preparation for our lecture, please pre-read pages 146-149 about protein structure.