These types of reactions are known as dehydration or condensation reactions. A monomer joins with another monomer with the release of a water molecule, leading to the formation of a covalent bond. The polymer is more than the sum of its parts: it acquires new characteristics, and leads to an osmotic pressure that is much lower than that formed by its ingredients this is an important advantage in the maintenance of cellular osmotic conditions. Macromolecules are made up of single units known as monomers that are joined by covalent bonds to form larger polymers. Proteins, carbohydrates, nucleic acids, and lipids are the four major classes of biological macromolecules-large molecules necessary for life that are built from smaller organic molecules. Breakdown of these macromolecules provides energy for cellular activities. Proteins are broken down by the enzymes pepsin and peptidase, and by hydrochloric acid. For instance, carbohydrates are broken down by amylase, sucrase, lactase, or maltase. Each macromolecule is broken down by a specific enzyme. This allows for easy absorption of nutrients by cells in the intestine.
For example, in our bodies, food is hydrolyzed, or broken down, into smaller molecules by catalytic enzymes in the digestive system. These reactions are similar for most macromolecules, but each monomer and polymer reaction is specific for its class. \( \newcommand\).ĭehydration and hydrolysis reactions are catalyzed, or “sped up,” by specific enzymes dehydration reactions involve the formation of new bonds, requiring energy, while hydrolysis reactions break bonds and release energy.