Hydrolysis and Dehydration Synthesis are two processes that are apart of biosynthesis. They are both related to water and other types of molecules. Hydrolysis uses water to separate molecules. This process differs based upon the type of science that it is being taught about. In Chemistry, hydrolysis is a chemical reaction.
This reaction involves the macro-molecule being separated into molecules that are more simple. The purpose of dehydration synthesis is to take water away to build something else. This process is done by removing a molecule to form water, which is H20. An example of this is with carbohydrates, which creates H2O + Disaccharide