Bio chap 4

    Cards (91)

    • What are enzymes?
      Biological catalysts that speed up reactions
    • What type of reactions do enzymes catalyze for growth?
      Anabolic reactions (building up)
    • What type of reactions release energy from large organic molecules?
      Catabolic reactions (breaking down)
    • What is metabolism?
      The sum of all reactions in a cell
    • What is Vmax?
      The maximum rate of reaction
    • What does specificity of the enzyme mean?
      Enzymes are specific to particular substrates
    • What are the two hypotheses of enzyme action?
      Lock and key, induced fit hypotheses
    • What part of the enzyme structure is the active site?
      Tertiary structure
    • What is the lock and key hypothesis?
      Active site is specific to the substrate
    • How does the lock and key hypothesis facilitate reactions?
      It reduces repulsion between molecules
    • What is the role of catalase?
      Breaks down hydrogen peroxide quickly
    • Why are substrates important?
      All reactions need substrates supplied
    • What form are nutrients often in?
      Polymers such as proteins
    • Why are extracellular enzymes important?
      They break down large nutrients for absorption
    • How do extracellular enzymes work in single-celled organisms?
      They release enzymes into the environment
    • How do extracellular enzymes work in multicellular organisms?
      Food is digested into smaller absorbable molecules
    • What are examples of extracellular enzymes in human digestion?
      Amylase and trypsin
    • What are the steps of starch digestion?
      Starch to maltose by amylase, maltose to glucose by maltase
    • Where is amylase produced and found?
      Produced by salivary glands and pancreas
    • Where is maltase found?
      Small intestine
    • How does amylase reach its site of action?
      Released in saliva and pancreatic juice
    • What type of enzyme is trypsin?
      Protease
    • What is trypsin's role?
      Catalyzes breakdown of proteins into peptides
    • Where is trypsin produced and where does it work?
      Produced in pancreas, works in small intestine
    • Why do enzymes lower activation energy?
      They hold molecules close together for reaction
    • What happens in the enzyme-product complex?
      Substrate reacts and products are formed
    • What is the induced fit hypothesis?
      Active site changes shape as substrate enters
    • How does bonding occur in the induced fit hypothesis?
      Weak interactions induce changes in enzyme structure
    • What are intracellular enzymes?
      Enzymes that act within cells
    • What are extracellular enzymes?

      Enzymes that work outside the cell
    • What are the factors affecting enzyme action?
      Concentration, temperature, pH
    • How does increasing temperature affect enzyme action?
      It increases kinetic energy and reaction rate
    • What does the temperature coefficient Q10 measure?
      Rate increase with a 10-degree rise
    • What is usually the Q10 of an enzyme-controlled reaction?
      2
    • How does an enzyme denature due to high temperatures?
      Bonds vibrate and break, changing shape
    • What is the optimum temperature for enzymes?
      Highest rate of activity
    • What are organisms found in hot areas called?
      Thermophiles
    • What is the optimum temperature for thermophiles?
      70 degrees
    • What are organisms found in cold environments called?
      Psychrophiles
    • What is the optimum temperature for psychrophiles?
      5 degrees
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