Final answer:
Enzymes are made of proteins because proteins can fold into complex shapes due to amino acid interactions, allowing the formation of active sites that are specific to substrates. This specificity aids in the precise control of biological reactions, making proteins ideal for catalyzing essential cellular processes.
Step-by-step explanation:
Enzymes are biological catalysts crucial for accelerating chemical reactions within the cell by lowering the activation energy required. These macromolecules are almost exclusively proteins. The reason for this is that proteins, which are made up of amino acids, have the unique ability to fold into complex three-dimensional shapes due to interactions between amino acids. This characteristic folding allows enzymes to possess an active site that is perfectly shaped to bind specific reactant molecules, greatly enhancing the rate at which the reaction can occur.
Moreover, the diversity of protein structures is extensive because there are 20 different amino acids that can be combined in various sequences, giving rise to a vast array of enzymes with highly specific functions. For example, each macromolecule in our bodies, like carbohydrates, proteins, and lipids, is broken down by a specific enzyme, such as amylase, pepsin, and lipase, respectively.
The tight specificity of enzymes to their substrates enables precise control over biological processes, making proteins ideal building blocks for enzymes. Their ability to accelerate reactions is crucial for processes such as DNA replication, metabolic pathways, and the digestion of food, highlighting the indispensability of protein-based enzymes in life.