Protein Folding

Hi all,

Today we looked at protein folding using three examples (silk / hair, amylase, and hemoglobin).  We saw how proteins assume complex shapes based on the properties of their amino acids, particularly their R-groups.  I'm posting the lecture notes below, but I would also recommend you take a look at a few animations.  Folding is a dynamic process, so it helps to look at a video:

Video resources
Protein Folding Interactive Tutorial
Short Protein Folding Animation

Here are the lecture notes: Protein Folding Lecture Notes

Homework
DCP write-up for Lab #2 (enzyme catalase and temperature) is due Friday.  Please check the blog post for your data if you haven't already.  If you need to find it, click the "labs" link on the right hand side under Buckets, and then find the post with your data.

Best of luck!
Mr. Hill

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.