2.4 Enzymes

• Enzymes are biological catalysts that affect both the structure and function within cells, tissues and organs.
• Enzymes speed up reactions that would otherwise require high temperatures, high pressures, extremes of pH and high concentrations of reactants, factors that would kill the organism.
• The product is released from the enzymes active site.
• The enzyme undergoes a conformational change which causes the conversion of substrate into product, forming an EP complex.
• The enzyme retains its original shape.
• The substrate enters the enzyme’s active site, forming an ES complex.
• Enzymes can speed up metabolic reactions by up to 10 times.
• A catalyst is a chemical that speeds up the rate of a reaction and remains unchanged and reusable at the end of the reaction.
• An enzyme is a protein molecule made by cells that acts as a catalyst and increases the rate of a chemical reaction.
• Enzymes are more specific than chemical catalysts.
• The cells in which enzymes are made and/or act can also regulate their production.
• Enzymes can only increase the rates of reaction up to a certain point, this is called the Vmax.
• Enzymes break down biological molecules, also known as catabolic reactions, that provide organisms with energy and building materials, such as respiration.
• Co-enzymes are non-protein substances that enhance the action of an enzyme.
• Enzymes catalyse a wide range of intracellular and extracellular reactions.
• Extracellular enzymes are enzymes that catalyse reactions outside cells.
• The product is released from the enzyme’s active site.
• The area on the enzyme that binds to and reacts with the substrate is called the active site.
• Enzymes are biological catalysts that speed up chemical reactions.
• Examples of intracellular enzymes include Helicase, Pepsin, Amylase, and Ligase.
• The Lock and Key model states that the substrate binds to the enzyme’s active site, forming an enzyme-substrate complex (ES complex).
• Examples of extracellular enzymes include Catalase, Amylase, and Lipase.
• All enzymes are proteins and are made in the cells by protein synthesis.
• The enzyme converts the substrate into product, forming an enzyme-product complex (EP complex).
• The enzyme retains its original shape.
• Intracellular enzymes are enzymes that catalyse reactions within cells.
• Enzymes form the biological molecules, also known as anabolic reactions, that make up living tissues, for example, the production of collagen.
• Molecules and nucleic acid test require 10 minutes to revise and 50 minutes to complete the test.
• Lipids are found within the phospholipid bilayer and help to maintain the fluidity of the membrane.
• Cholesterol is an amphipathic molecule (like phospholipids), meaning it has both hydrophilic and hydrophobic regions.
• Enzyme action involves the use of ATP, which stands for Adenosine triphosphate, the energy currency.
• Metabolic reactions are the sum of all reactions in the organism.
• Activation energy is the energy required to start a reaction.
• Metabolic reactions are the sum of all reactions in the organism.
• A change in pH affects enzyme structure because H+ ions interact with polar and charged R groups in tertiary structures, breaking the bonds/interactions between R groups, leading to loss of tertiary structure.
• An increase in temperature increases enzyme activity because it increases particles’ kinetic energy, causing them to move faster and collide more often, leading to more successful collisions between the active site and substrate.
• The primary structure of a protein is determined by its amino acid sequence.
• Anabolic reactions involve the building up of larger molecules.
• Enzymes are biological catalysts that speed up chemical reactions.
• The two models used to illustrate enzyme actions are Lock-and-key and Induced fit.