Metabolic Pathways

    Cards (19)

    • What are metabolic pathways?
      Integrated and controlled pathways of enzyme-catalysed reactions within a cell
    • What types of steps can metabolic pathways have?
      Reversible steps, irreversible steps, and alternative routes
    • What are the two types of reactions within metabolic pathways?
      Anabolic and catabolic reactions
    • What do anabolic reactions do?
      Build up large molecules from small molecules and require energy
    • What do catabolic reactions do?

      Break down large molecules into smaller molecules and release energy
    • How are metabolic pathways controlled?
      By the presence or absence of particular enzymes and the regulation of the rate of reaction of key enzymes
    • What is the role of the active site of an enzyme?
      It affects activation energy and the affinity of the substrate and products for the active site
    • How do substrate and product concentrations affect enzyme reactions?
      They influence the direction and rate of enzyme reactions
    • What occurs during induced fit in enzymes?
      The active site changes shape to better fit the substrate after the substrate binds
    • What is the affinity of substrate molecules for the active site?

      Substrate molecules have a high affinity for the active site
    • What is the affinity of products for the active site after the reaction?
      Products have a low affinity allowing them to leave the active site
    • How can the direction of reversible metabolic reactions be influenced?
      By the presence of a substrate or the removal of a product
    • What are the types of enzyme inhibition that control metabolic pathways?
      • Competitive inhibition
      • Non-competitive inhibition
      • Feedback inhibition
    • How do competitive inhibitors affect enzyme activity?
      They bind at the active site preventing the substrate from binding
    • Can competitive inhibition be reversed?
      Yes, by increasing substrate concentration
    • How do non-competitive inhibitors affect enzyme activity?
      They bind away from the active site and change the shape of the active site
    • Can non-competitive inhibition be reversed by increasing substrate concentration?
      No, it cannot be reversed by increasing substrate concentration
    • What is feedback inhibition in metabolic pathways?
      When the end-product reaches a critical concentration and inhibits an earlier enzyme
    • What is the effect of feedback inhibition on the metabolic pathway?
      It blocks the pathway and prevents further synthesis of the end-product
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