Workers get names depending on what they do. The three most common kinds of workers are transporters, enzymes, and structural proteins.

Transporters are the workers who carry things into and out of the factory. Since they only carry things that fit their Instruction, they act as a cross between doors, conveyer belts, and guards.

Most workers assemble, disassemble, or change things, and are lumped into the general category called enzymes. Enzymes are given more specific names based on what they do or what materials they work with. For instance, the worker which changes milk sugar (lactose) into a digestible form is called lactase.

How does a worker change sugar? The answer to this question gets at the heart of what all enzymes do: enzymes chemically change molecules. Enzymes change molecules in a number of ways: they stick several together, they cut one into parts, they rearrange a molecule's pieces. Since this site isn't a chemistry reference, we won't talk about the details of the molecules or the changes enzymes make to them. Suffice it to say that just as cutting and folding paper can make tremendously complex origami figures, the simple task of working on molecules accounts for all of the complexity of life.

There's another kind of change workers make to molecules, in addition to joining, cutting, and rearranging them: they hang onto them. This is what activators and repressors do when they cover up promoters in Life's Instruction Book. Yes, that means that the Instruction Book is just a molecule -- a very complex and special molecule called DNA. Even the workers themselves are molecules, and like DNA, they're very large and complex. The notes and messages workers pass between each other are molecules as well.

Not all workers are enzymes, engaged in making molecular origami. Some workers have a special instruction: just stand there. These kinds of workers make up the structure of the factory, and are called structural proteins. Just as a foundry can turn out the I-beams that support its roof, Life's origami factories turn out strong workers to make up the structure of the factory. In fact, nearly all living things need to do this. For example, fingernails and hair are made of trillions of workers called keratin stuck together.