Here's how it works:

* Dehydration: A water molecule (H₂O) is removed from the monomers. This usually involves removing a hydroxyl group (-OH) from one monomer and a hydrogen atom (-H) from the other monomer.

* Synthesis: The monomers, now with open bonding sites, form a covalent bond, linking them together.

This process is fundamental in building complex biological molecules like:

* Carbohydrates: Simple sugars (monomers) like glucose combine to form complex carbohydrates like starch and cellulose.

* Proteins: Amino acids (monomers) link together to form polypeptide chains (polymers).

* Nucleic Acids: Nucleotides (monomers) join to form DNA and RNA.

* Lipids: Fatty acids and glycerol (monomers) combine to form fats and phospholipids.

Think of it like building a chain out of individual links. Each link is a monomer, and the act of connecting them together is dehydration synthesis. The water molecule removed is like the "waste" of the construction process.