The chemical process in which smaller compounds are joined to form larger compounds is called dehydration synthesis or condensation reaction.

Here's how it works:

* Monomers: Smaller units of molecules are called monomers.

* Polymers: Larger molecules formed by joining monomers are called polymers.

* Dehydration Synthesis: During this process, a molecule of water is removed from the monomers as they join together. This forms a covalent bond between the monomers, creating a larger molecule.

Examples:

* Carbohydrates: Simple sugars (monosaccharides) are joined together to form complex carbohydrates (polysaccharides) through dehydration synthesis.

* Proteins: Amino acids are linked together to form proteins through dehydration synthesis.

* Lipids: Fatty acids and glycerol are joined together to form fats (triglycerides) through dehydration synthesis.

Key Takeaway: Dehydration synthesis is an important process in the formation of essential biological molecules. It allows for the creation of complex structures from simple building blocks.