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Active Transport quiz #3

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  • What distinguishes primary active transport from secondary active transport?
    Primary active transport uses energy directly from ATP hydrolysis to move molecules against their concentration gradient, while secondary active transport uses the energy from another molecule's concentration gradient, not directly from ATP.
  • How does the sodium-potassium pump help maintain cellular homeostasis?
    By exporting sodium and importing potassium, the sodium-potassium pump maintains essential ion gradients across the cell membrane, which are crucial for processes like nerve impulse transmission and cell volume regulation.
  • Why is secondary active transport considered indirectly dependent on ATP?
    Secondary active transport is indirectly dependent on ATP because the concentration gradient that powers it (such as the sodium gradient) is established by primary active transport, which uses ATP.
  • What is the main difference between primary and secondary active transport?
    Primary active transport uses energy directly from ATP hydrolysis, while secondary active transport uses the energy from another molecule's concentration gradient.
  • Why does active transport require energy?
    Active transport requires energy because it moves molecules against their concentration gradients, from areas of low concentration to areas of high concentration.
  • How does the sodium-potassium pump function as an example of primary active transport?
    The sodium-potassium pump uses ATP to export 3 sodium ions out of the cell and import 2 potassium ions into the cell, both against their concentration gradients.
  • What is the role of ATP in primary active transport?
    ATP provides the direct energy needed for membrane proteins to move molecules against their concentration gradients.
  • How does secondary active transport use the sodium gradient to move glucose?
    Secondary active transport uses the energy released as sodium moves down its concentration gradient to power the transport of glucose against its gradient.
  • Why is secondary active transport considered indirectly dependent on ATP?
    Because the concentration gradient that powers secondary active transport (like the sodium gradient) is established by primary active transport, which uses ATP.
  • How does the sodium-potassium pump help maintain cellular homeostasis?
    By exporting sodium and importing potassium, the sodium-potassium pump maintains essential ion gradients across the cell membrane, which are crucial for processes like nerve impulse transmission and cell volume regulation.