Question

Although facilitated diffusion is clearly happening, the indicated ion concentrations are not

changing. That is because this image is actually missing a very important protein called the
sodium-potassium pump. Think about what you know about the concentration gradients.
(Remember: ions typically flow from areas of high concentration to areas of low
concentration, but it can go in the other direction, as well.)
a. What must this pump be doing to maintain the concentration gradient?
b. What kind of transport is it doing - active or passive?
c. Which direction must each ion be moving through the pump?
A. Active transport
B. Passive transport
C. Facilitated diffusion

Answer 1

The sodium-potassium pump actively transports Na+ out of the cell and K+ into the cell, requiring ATP for energy, therefore it is an example of active transport. It complements facilitated diffusion by maintaining ion concentration gradients essential for various cellular functions.

Step-by-step explanation:

The sodium-potassium pump is an essential protein involved in maintaining ion concentration gradients across the cell membrane. To answer the questions:

• a. The pump must be actively transporting sodium (Na+) and potassium (K+) ions against their concentration gradients to maintain the proper ionic balance within the cell.
• b. This is an example of active transport because it requires energy in the form of ATP to move ions against their respective concentration gradients.
• c. Sodium ions (Na+) are moved out of the cell, and potassium ions (K+) are moved into the cell by the pump. This process is essential because facilitated diffusion cannot actively maintain the concentration gradients.

Facilitated diffusion is a passive transport mechanism and occurs without the need for cellular energy, moving substances down their concentration gradient through specific protein channels. In contrast, the sodium-potassium pump, which requires energy, complements facilitated diffusion by maintaining the concentration gradients that facilitated diffusion relies on.