Final answer:
In biology, substrates are molecules that enzymes act on to catalyze chemical reactions. Enzymes, which are typically proteins, have an active site specifically designed to bind to their substrates, facilitating a chemical reaction. Without the correct substrates, enzymes could not perform their catalytic functions.
Step-by-step explanation:
What Are Substrates in Biology?
In biology, a substrate is a molecule upon which an enzyme acts. Enzymes are biological catalysts that accelerate chemical reactions in the body by lowering the activation energy required for these reactions to occur. They are typically proteins with one or more polypeptide chains. These enzymes have an active site that provides a unique chemical environment, which is perfectly suited for the conversion of specific chemical reactants, known as substrates, into something else through the reaction.
The binding of the substrate to the enzyme's active site involves a precise interaction, often described as a 'lock and key' model or an 'induced fit.' This specificity ensures that enzymes catalyze the correct reactions. Once bound, the enzyme can alter the substrate's bonds, bringing substrates together in the correct orientation, enhancing the conditions for a reaction, or sometimes forming transient covalent bonds with the substrate, all of which contribute to a more efficient biochemical reaction.
The role of substrates in enzymatic reactions is crucial because without the correct substrate, an enzyme is unable to perform its function. This is exemplified in a typical enzymatic reaction diagram, where the substrate reactant binds to the enzyme's active site, undergoes the catalyzed reaction, and is then released as a different molecule or molecules.