Question

dehydration synthesis or hydrolysis
occurs when water leaves the reaction
occurs when water goes into the reaction
occurs when making a polymer/molecule
occurs when polymers/molecules are broken down into monomers

Explanation:

Dehydration synthesis is a reaction where water is removed as a by - product when monomers combine to form polymers. Hydrolysis is the opposite, where water is added to break polymers into monomers. So, when water leaves the reaction, it's dehydration synthesis. When water goes into the reaction, it's hydrolysis. When making a polymer/molecule, it's dehydration synthesis. When polymers/molecules are broken down into monomers, it's hydrolysis.

Answer:

Occurs when water leaves the reaction: Dehydration Synthesis
Occurs when water goes into the reaction: Hydrolysis
Occurs when making a polymer/molecule: Dehydration Synthesis
Occurs when polymers/molecules are broken down into monomers: Hydrolysis