Introduction to Enzymes
Enzymes are biocatalysts that speed up reactions. They’re crucial for metabolic processes, functioning under mild conditions without being consumed. Each enzyme's three-dimensional structure provides its unique catalytic capabilities.
Enzyme-Substrate Specificity
Enzyme specificity is determined by the active site's shape. The 'lock and key' model illustrates this specificity. However, the 'induced fit' model accounts for conformational adjustments upon substrate binding, enhancing catalysis.
Catalysis and Activation Energy
Enzymes catalyze reactions by lowering activation energy, allowing the reaction to proceed faster. They achieve this without altering the reaction equilibrium, just the rate at which it is reached.
Michaelis-Menten Kinetics
The Michaelis-Menten equation describes the rate of enzymatic reactions. It shows the relationship between substrate concentration and reaction rate, revealing an enzyme's affinity for its substrate.
Factors Affecting Enzyme Activity
Enzyme activity is affected by temperature, pH, and substrate concentration. Each enzyme works optimally at a characteristic pH and temperature. Deviations can denature the enzyme, ceasing function.
Allosteric Regulation
Enzymes can be regulated by molecules that bind at sites other than the active site, known as allosteric sites. This binding causes conformational changes that alter enzyme activity.
Inhibitors and Drug Design
Understanding enzyme kinetics aids in designing drugs that inhibit enzymes. Competitive inhibitors resemble substrates, while non-competitive inhibitors bind elsewhere, influencing enzyme activity without competing.