Introduction to a new and fun form of isomer!

In some sense, all science comes down to understanding energy. If someone ever asks you why something happens, you can answer: "The second law of thermodynamics." It's never wrong, but also may not be very helpful unless you can make the connection to more local causes. This is the beginning of the discussion, with a biological theme.

A common theme in biology is how large "macromolecules" from subunits, usually known as monomers. Really, I'm underselling this point. You will see it over and over for the next several months.
Two linked together is a "dimer," three is a trimer...you get the idea. We usually get lazy after "tetramer" and start calling them "oligomer" for groups that are in the range of 5-10 and then "polymer," when you get to many units…hundreds or thousands…even more. Hey…one common organic compound we will get to know is known as an "ester." What do you think we call a fiber made of many of these linked together?