Summary and Exam Tips for Enzymes
Enzymes is a subtopic of Molecular Biology, which falls under the subject Biology in the IB DP curriculum. Enzymes are globular proteins that act as biological catalysts, increasing the rate of biochemical reactions by lowering the activation energy threshold. They are composed of long chains of amino acids, forming a specific three-dimensional shape. Enzymes are not consumed in reactions and can be reused. They are named after their substrates with the suffix '-ase', such as lipase for lipids.
The active site of an enzyme is where the substrate binds, and this interaction is highly specific due to complementary shapes and chemical properties. The lock-and-key hypothesis and the induced fit model describe how substrates interact with active sites. Enzyme catalysis involves molecular motion and substrate collisions with the active site, influenced by factors like temperature, pH, and substrate concentration. Enzymes can be denatured by extreme temperatures and pH levels, leading to loss of function.
Immobilized enzymes are widely used in industries, offering benefits like increased stability and cost savings. They are employed in various sectors, including food production, biotechnology, and medicine. For instance, immobilized lactase is used to produce lactose-free milk, aiding those with lactose intolerance.
Exam Tips
- Understand Key Concepts: Focus on the structure and function of enzymes, including the active site, enzyme-substrate complex, and models of enzyme action.
- Memorize Factors Affecting Enzyme Activity: Remember how temperature, pH, and substrate concentration influence enzyme activity and stability.
- Practice Application: Be familiar with industrial applications of enzymes, such as immobilized enzymes in food and biotechnology.
- Visualize Models: Use diagrams to understand the lock-and-key and induced fit models, as well as enzyme catalysis processes.
- Revise Denaturation: Know how denaturation affects enzyme structure and function, and the conditions that cause it.
