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Active Transport quiz #1

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  • What is the main difference between primary and secondary active transport in terms of their energy sources?
    Primary active transport uses energy directly from ATP hydrolysis to move molecules against their concentration gradients, while secondary active transport uses the energy from the concentration gradient of another molecule, which was established by primary active transport, and does not use ATP directly.
  • How does the sodium-potassium pump function as an example of primary active transport?
    The sodium-potassium pump uses ATP to export three sodium ions out of the cell and import two potassium ions into the cell, moving both ions against their concentration gradients and maintaining essential ion gradients across the plasma membrane.
  • Describe how secondary active transport works using the sodium-glucose transporter as an example.
    In the sodium-glucose transporter, sodium moves down its concentration gradient into the cell, releasing energy that is used to transport glucose against its concentration gradient into the cell. This process does not use ATP directly but relies on the sodium gradient created by primary active transport.
  • Why is energy required for active transport, and what direction do molecules move during this process?
    Energy is required for active transport because molecules are moved against their concentration gradients, from areas of low concentration to areas of high concentration, which is energetically unfavorable and cannot occur by diffusion alone.
  • What is the main difference between primary and secondary active transport in terms of their energy sources?
    Primary active transport uses energy directly from ATP hydrolysis, while secondary active transport uses the energy from the concentration gradient of another molecule and does not use ATP directly.
  • How does the sodium-potassium pump function as an example of primary active transport?
    The sodium-potassium pump uses ATP to export three sodium ions out of the cell and import two potassium ions into the cell, moving both ions against their concentration gradients.
  • Describe how secondary active transport works using the sodium-glucose transporter as an example.
    In the sodium-glucose transporter, sodium moves down its concentration gradient into the cell, releasing energy that is used to transport glucose against its concentration gradient into the cell.
  • Why is energy required for active transport, and what direction do molecules move during this process?
    Energy is required because molecules are moved against their concentration gradients, from areas of low concentration to areas of high concentration, which is energetically unfavorable.
  • What role does ATP play in primary active transport but not in secondary active transport?
    ATP is directly hydrolyzed to provide energy for primary active transport, whereas secondary active transport relies on the energy from another molecule's concentration gradient and does not use ATP directly.
  • How does the sodium concentration gradient established by primary active transport facilitate secondary active transport?
    The sodium concentration gradient created by primary active transport allows sodium to move back into the cell down its gradient, and this movement provides the energy needed to transport other molecules, like glucose, against their gradients in secondary active transport.