Final answer:
Proteins, carbohydrates, and nucleic acids are three categories of essential organic polymers made up of monomers linked by covalent bonds. These polymers are important for various biological processes, including energy provision and structural support, and their monomers are connected or separated by dehydration and hydrolysis reactions respectively.
Step-by-step explanation:
The topic of organic molecules essential for life includes proteins, carbohydrates, nucleic acids, and lipids. Among these, proteins, carbohydrates, and nucleic acids are polymers, which means they are composed of smaller units known as monomers. These monomers are joined together by covalent bonds during dehydration synthesis (also called condensation reactions), where a molecule of water is released to form a new bond.
Polymers display distinct properties that differentiate them from their monomer constituents, including a vastly reduced osmotic pressure beneficial for maintaining cellular conditions. Conversely, polymers can be broken down into their monomers through hydrolysis reactions, which involve the utilization of water to break the covalent bonds. Both types of reactions are catalyzed by specific enzymes.
Carbohydrates are a major class of macromolecules that function as a primary energy source in cells and provide structural support within organisms. These are classified by the number of sugar units: monosaccharides (single units), disaccharides (two units), and polysaccharides (multiple units), and are linked by glycosidic bonds formed via dehydration reactions.