Enzymes, the body's workmen, are somewhat major characters in Once Upon a Time... Life. They work with DNA and
Mr. Enzyme

An Enzyme in The Cell Planet

help with other things, like giving the Red Blood Cells Oxygen and Carbon Dioxide, as well as other jobs. They appear to be wearing a bib overall and a baseball cap with an arrow on it. Some Enzymes where Shirts that go down to their feet, and have no arrow on their hats.