Final answer:
Enzymes are biological catalysts that work best at an optimum pH and temperature, with conditions specific to each enzyme. The active site's precise conditions ensure efficiency but can lead to denaturation if the environment deviates too far from the optimum.
Step-by-step explanation:
Enzymes are biological catalysts which work best while at optimum pH or even temperature. Biological catalysts are protein-based substances designed to accelerate chemical reactions by lowering the activation energy required, usually within a specific and narrow range of pH and temperature conditions. The term 'optimum' refers to the ideal conditions under which an enzyme is most effective. These conditions vary for different enzymes depending on their role and the organism from which they originate.
Enzymes also have active sites that are specifically designed to bind to their substrate(s), often changing shape slightly to achieve a perfect fit in a process known as induced fit. While increasing environmental temperature generally speeds up reaction rates, temperatures outside of an enzyme's optimum range can lead to denaturation—where the enzyme loses its three-dimensional structure and, consequently, its function.
Similarly, while environmental pH can enhance enzyme activity, extreme pH values can also cause denaturation by disrupting ionic bonds and altering the enzyme's active site.