Final answer:
Enzymes work by lowering the activation energy of chemical reactions, allowing these reactions to occur more easily and quickly. The enzyme binds to substrates to form an enzyme-substrate complex that can facilitate the reaction. Enzymes are specific to substrates and are not consumed in the reaction.
Step-by-step explanation:
Enzymes are biological catalysts that speed up chemical reactions in living organisms. One of the key functions of enzymes is to lower the activation energy required for chemical reactions. Activation energy is the energy necessary to initiate a chemical reaction, and by reducing this energy requirement, enzymes facilitate the reaction to occur more easily and at a faster rate. The way enzymes accomplish this is by binding to reactant molecules, known as substrates, to form an enzyme-substrate complex. This complex can lower activation energy by positioning substrates optimally for the reaction to occur, by contorting the substrates to a transition state favorable for the reaction, or by directly participating in the reaction and forming temporary bonds with the substrates.
Enzymes possess a unique active site that is specific to their substrates, ensuring that they only catalyze specific reactions. After the reaction, the enzyme returns to its original state and can then catalyze new reactions, meaning that enzymes are not consumed by the reactions they catalyze.
An allosteric inhibitor, about enzyme activity, binds to a site other than the enzyme's active site. This binding causes a change in the conformation of the enzyme, which can decrease its affinity for the substrate, effectively decreasing the activity of the enzyme.