Episode Details

Before hearing from Intelligent Design advocates, we thought we’d give our listeners some useful background information about how cells work …. it turns out it’s all about making shapes out of string.

Before we present our interviews with Drs. Michael Behe and Jonathan McLatchie (both leading proponents of Intelligent Design), we feel we should give our listeners a quick Cell Biology 101 to explain some of the concepts that will frequently come up in those interviews, and which easily mislead non-experts. So, in this episode we’ll talk about how cells make proteins, and how it’s the sequence of amino acids (which is directly decoded from the gene sequences) which determines the 3-dimensional (3D) shape of the protein, and that in turn gives the protein its functionality.

In this casual conversation, given at a NON-EXPERT level, Scott and I talked about:

• the string of DNA gets decoded into a long string of amino acids (we came up with two metaphors for this long string: toothpaste being squeezed out of a tube, and “Silly String” being squirted from an aerosol can at a party)
• that string of amino acid is called a protein; protein adopts a 3D shape that directly gives it its functionality
• the toothpaste / Silly String forms a long strand which flops all over itself, forming loops and folds and a completely disorganized mess; the strand of protein would also form a disorganized mess, except for the fact that the amino acids themselves begin to interact with each other and generate attractive/repulsive forces that cause it to fold and compact the loops into a particular 3D shape
• force #1: electrostatic attraction … a series of positive and negative charges which strongly attract each other, kind of like a sock sticking to a towel when you pull them out of the dryer, and have to peel the sock off
• force #2: electrostatic repulsion … a series of positive versus positive charges (or negative versus negative charges) which push each other apart, kind of like your hair standing on its end when you put your hand on a van de Graf generator at a science museum
• force #3: hydrophilic/hydrophobic attraction … a series of “water-loving” amino acids want to stick together (like sticking a piece of paper to a window just by making it wet); in the same way, “wate