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Active Transport quiz

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  • What is the main requirement for active transport to move molecules across a membrane?
    Active transport requires energy to move molecules against their concentration gradients, from areas of low to high concentration.
  • What are the two main types of active transport?
    The two main types of active transport are primary active transport and secondary active transport.
  • How is primary active transport powered?
    Primary active transport is powered directly by ATP hydrolysis.
  • What is the key difference between primary and secondary active transport?
    Primary active transport uses ATP directly, while secondary active transport is powered by the concentration gradient of another molecule.
  • What membrane protein is a classic example of primary active transport?
    The sodium-potassium pump is a classic example of primary active transport.
  • How many sodium and potassium ions does the sodium-potassium pump move per cycle, and in which directions?
    The sodium-potassium pump exports three sodium ions out of the cell and imports two potassium ions into the cell per cycle.
  • Why is the sodium-potassium pump considered an antiporter?
    It is considered an antiporter because it moves sodium and potassium ions in opposite directions across the membrane.
  • What is the role of ATP in the sodium-potassium pump?
    ATP provides the energy required for the pump to move sodium and potassium ions against their concentration gradients.
  • How does secondary active transport obtain the energy needed to move molecules?
    Secondary active transport uses the energy stored in the concentration gradient of another molecule, not directly from ATP.
  • What is a classic example of secondary active transport?
    The sodium-glucose transporter is a classic example of secondary active transport.
  • How does the sodium-glucose transporter work?
    It uses the energy from sodium ions moving down their concentration gradient to power the movement of glucose against its gradient.
  • How is the sodium gradient, used in secondary active transport, established?
    The sodium gradient is established by primary active transport, specifically by the sodium-potassium pump using ATP.
  • Does secondary active transport directly use ATP? Explain.
    No, secondary active transport does not directly use ATP; it relies on the gradient created by primary active transport.
  • What happens to the concentrations of sodium and potassium inside and outside the cell due to the sodium-potassium pump?
    There is a low concentration of sodium and a high concentration of potassium inside the cell, and the opposite outside the cell.
  • Why is understanding both types of active transport important for cell biology?
    Understanding both types is essential for comprehending how cells manage energy and maintain necessary concentration gradients for survival.