University:
University of Ottawa
Course:
BIO 1130 | Introduction to Organismal Biology
Academic year:

2024
Views:

396

Pages:

2
Author:

xxzakxx 45

Enzyme Activity: Key Points What are Enzymes? Biological catalysts: Speed up chemical reactions without being consumed. Mostly proteins: Made up of amino acid chains with specific 3D structures. Highly specific: Each enzyme typically catalyzes one specific reaction. Essential for life: Regulate metabolic pathways and cellular processes. How Enzymes Work Active site: The region on the enzyme where the substrate binds. Substrate: The molecule that the enzyme acts upon. Enzyme-substrate complex: Formed when the substrate binds to the active site. Lower activation energy: Enzymes reduce the energy required for a reaction to start. Induced fit model: The active site slightly changes shape to fit the substrate perfectly. Factors Affecting Enzyme Activity Temperature: Optimal temperature: The temperature at which an enzyme works best. Denaturation: High temperatures can disrupt the enzyme's structure, causing it to lose function. pH: Optimal pH: The pH at which an enzyme works best. Changes in pH can alter the enzyme's shape and charge, affecting its activity. Substrate concentration: Increased substrate concentration generally increases the rate of reaction until the enzyme becomes saturated. Enzyme concentration: Increased enzyme concentration increases the rate of reaction if there is enough substrate. Inhibitors: Competitive inhibitors: Compete with the substrate for the active site. Non-competitive inhibitors: Connects to another area on the enzyme, changing its form and function. Enzyme Regulation Allosteric regulation: Other molecules attach to a site that is not the main active area, affecting the enzyme's action. Inhibition by end-product: The enzyme is inhibited by a final product of the metabolic pathway. Covalent modification: Addition or removal of chemical groups can activate or deactivate enzymes. Examples of Enzymes Amylase: Breaks down starch into sugars. Pepsin: Digests proteins in the stomach. Catalase: Breaks down hydrogen peroxide into water and oxygen. DNA polymerase: Replicates DNA. Additional Notes Cofactors: Non-protein molecules that help some enzymes function. Coenzymes: Organic cofactors (e.g., vitamins). Isozymes: They are variant types of the same enzyme. These isozymes perform identical reaction but possess distinct features.