Overview
Enzymes are biological catalysts that make life-sustaining chemical reactions occur faster and more efficiently. This topic explores how enzymes function, how they are affected by environmental conditions, and how energy transformation—primarily involving ATP—drives essential biological processes.
Key Concepts and Structures
- Enzyme Function: Enzymes lower activation energy, enabling metabolic reactions to proceed at life-compatible rates.
- Active Site and Substrate: The region on an enzyme where the substrate binds and the reaction occurs.
- Enzyme Specificity: Each enzyme acts on a specific substrate due to complementary shapes (lock-and-key or induced fit models).
- Factors Affecting Enzymes: Temperature, pH, and substrate concentration influence enzyme activity; extreme conditions can denature enzymes.
- Inhibitors: Competitive and noncompetitive inhibitors regulate enzyme activity by altering substrate access or enzyme shape.
- ATP: Adenosine triphosphate is the energy currency of cells, storing and transferring energy for biochemical reactions.
- Energy Coupling: ATP hydrolysis powers endergonic (energy-requiring) reactions in cells.
- Metabolic Pathways: Sequences of enzyme-mediated reactions; catabolic pathways release energy, anabolic pathways consume it.
Quick Tip
Remember: enzymes don’t supply energy—they enable the reaction to happen faster. Focus on how changes in pH or temperature impact enzyme shape, and therefore function.