What Are Enzymes and Their Role in Biochemical Reactions?
Enzymes are specialized proteins that act as biological catalysts, accelerating biochemical reactions without being consumed. They lower the activation energy required for reactions to occur, enabling essential processes like digestion and DNA replication to happen efficiently in living organisms at moderate temperatures.
Key Principles of Enzyme Function
Enzymes work by binding to substrates at their active sites, forming an enzyme-substrate complex that facilitates the reaction. This specificity ensures precise control over metabolic pathways. The Michaelis-Menten model describes enzyme kinetics, where reaction rate depends on substrate concentration until saturation is reached.
Practical Example: Lactase in Digestion
Consider lactase, an enzyme in the small intestine that breaks down lactose into glucose and galactose. In individuals with lactose intolerance, low lactase activity leads to undigested lactose causing digestive issues, illustrating how enzymes enable nutrient absorption and how their deficiency impacts health.
Factors Affecting Enzyme Activity and Real-World Applications
Enzyme activity is influenced by temperature (optimal around 37°C for human enzymes, with denaturation above), pH (varying optima, e.g., pepsin at pH 2), substrate concentration, and inhibitors/activators. Understanding these allows applications in biotechnology, such as designing stable enzymes for industrial processes like biofuel production.