Enzymes & Metabolism

• What are enzymes classified as?

  Biological catalysts
• How do enzymes affect chemical reactions?

  They speed up reactions without being consumed
• What is a catalyst?

  A substance that increases reaction rate
• What does metabolism refer to?

  All chemical reactions in living organisms
• Why are enzymes crucial in metabolism?

  They control and regulate chemical reactions
• What are anabolic reactions?

  Build larger molecules from smaller ones
• What type of energy is required for anabolic reactions?

  Energy required: Endergonic reactions
• What are catabolic reactions?

  Break down larger molecules into smaller ones
• What type of energy is released during catabolic reactions?

  Energy released: Exergonic reactions
• What happens during hydrolysis reactions?

  Water is added to break down molecules
• What is the structure of enzymes?

  Globular proteins with a specific active site
• What occurs at the active site of an enzyme?

  The substrate binds and the reaction is catalyzed
• What is the induced-fit model?

  The active site changes shape to fit the substrate
• What is required for a reaction to occur according to collision theory?

  Substrate and enzyme must collide
• What is immobilization in enzyme reactions?

  Anchoring substrates or enzymes to increase efficiency
• Why are enzymes specific to their substrates?

  Due to the shape of the active site
• What is denaturation in enzymes?

  Changes in temperature or pH alter enzyme shape
• What happens to enzyme activity as temperature increases?

  Rate increases until the enzyme denatures
• How does pH affect enzyme activity?

  Each enzyme has an optimal pH
• What happens to reaction rate as substrate concentration increases?

  Rate increases until all active sites are saturated
• What do the two curves in the enzyme activity graph represent?

  Different enzymes with different optimal pH levels
• How are reaction rates measured in enzyme-catalyzed reactions?

  By disappearance of substrate or appearance of product
• What is activation energy?

  The energy required for a reaction to happen
• How do enzymes affect activation energy?

  They lower the activation energy needed
• What do graphs showing enzyme activity represent?

  Models evaluated using experimental data
• How does enzyme activity depend on concentration changes?

  Depends on substrate concentration and metabolic pathways