AP Biology Questions on Active Transport: Sodium-Potassium Pump

📚 Quick Study Guide

• 🧬 The sodium-potassium pump is a transmembrane protein that actively transports sodium ions ($Na^+$) out of the cell and potassium ions ($K^+$) into the cell.
• ⚡ This process maintains the electrochemical gradient across the cell membrane, crucial for nerve impulse transmission and muscle contraction.
• ⚙️ For each ATP molecule hydrolyzed, the pump transports 3 $Na^+$ ions out and 2 $K^+$ ions in.
• 🧪 The pump is an example of primary active transport, using ATP directly as the energy source.
• 🌡️ The pump's activity is influenced by factors such as temperature, ATP availability, and ion concentrations.

🧪 Practice Quiz

1. Which of the following best describes the primary function of the sodium-potassium pump?
   1. A) To facilitate the diffusion of sodium ions into the cell.
   2. B) To actively transport sodium ions out of the cell and potassium ions into the cell.
   3. C) To passively transport potassium ions out of the cell.
   4. D) To maintain equal concentrations of sodium and potassium ions inside and outside the cell.
2. What is the energy source directly used by the sodium-potassium pump to perform its function?
   1. A) Glucose
   2. B) ATP
   3. C) GTP
   4. D) Electrochemical gradient
3. How many sodium ions ($Na^+$) are transported out of the cell for every ATP molecule hydrolyzed by the sodium-potassium pump?
   1. A) 1
   2. B) 2
   3. C) 3
   4. D) 4
4. How many potassium ions ($K^+$) are transported into the cell for every ATP molecule hydrolyzed by the sodium-potassium pump?
   1. A) 1
   2. B) 2
   3. C) 3
   4. D) 4
5. The sodium-potassium pump is an example of which type of transport?
   1. A) Facilitated diffusion
   2. B) Osmosis
   3. C) Primary active transport
   4. D) Secondary active transport
6. What is the primary role of the sodium-potassium pump in nerve cells?
   1. A) To generate action potentials.
   2. B) To maintain the resting membrane potential.
   3. C) To facilitate the release of neurotransmitters.
   4. D) All of the above.
7. Which of the following is a direct consequence of the sodium-potassium pump's activity?
   1. A) Increased concentration of $Na^+$ inside the cell.
   2. B) Decreased concentration of $K^+$ inside the cell.
   3. C) Maintenance of a negative charge inside the cell relative to the outside.
   4. D) Equal distribution of $Na^+$ and $K^+$ across the cell membrane.