What is lost each time a monomer is combined?

In the molecular world, the small subunits that ultimately link together to form larger molecules are called monomers, which literally means "single unit" (mono = one). When a bunch of monomers join together into a much larger molecule, they form a polymer, meaning "many units" (poly = many).

There is a process by which this joining usually occurs, called dehydration synthesis. Two monomers line up next to each other, and just when you think they’re going to start line dancing, a hydrogen (H) from one monomer binds with a hydroxyl group (OH) from another monomer, and voilà! A water molecule is born: H+ + OH- = H2O.

Sometimes the thing that is being removed is the water molecule because the system is called the dehydration synthesis.

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