Final answer:
Carbohydrates and proteins are built up through dehydration reactions, where a water molecule is removed as monomers bond to form polymers.
Step-by-step explanation:
Carbohydrates and proteins are built up from their basic building blocks by the removal of a water molecule between each two units, which is known as a dehydration or condensation reaction. These reactions involve monomers, such as amino acids for proteins and monosaccharides for carbohydrates, joining together to form polymers. Each time a bond is formed between two monomers, a water molecule is released; this is essential for the formation of proteins with peptide bonds and carbohydrates with glycosidic bonds.