The sodium concentration in a cell is 10 times less than the...

The sodium concentration in a cell is 10 times less than the concentration in the surrounding fluid. How can the cell move sodium out of the cell? (Explain your answer.)
a. passive transport
b. receptor-mediated endocytosis
c. active transport
d. facilitated diffusion

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Active Transport

Active transport is the process by which cells move molecules against their concentration gradient using energy, typically in the form of ATP. This mechanism is essential when the movement of substances occurs from an area of lower concentration to an area of higher concentration, contrary to what would normally occur via diffusion.

Concentration Gradient

A concentration gradient refers to the difference in the amount of a substance between two regions, such as inside and outside of a cell. This gradient drives passive diffusion; however, to move substances against this natural flow, cells must expend energy through active transport mechanisms.

Transcript

00:01 Okay, so here we have a scenario where we have a cell in solution, and the concentration of sodium ions in the solution is 10 times greater than that in the cell.

00:12 And so we need to figure out a way to get this sodium ion right here out of the cell.

00:20 And there are a few ways that could potentially happen.

00:22 We have our passive transport.

00:29 We have facilitated diffusion.

00:37 We have endocytosis and we have active transport.

00:52 So why don't we go ahead and start looking at passive transport? passive transport actually wouldn't work in this situation.

00:59 And that's because passive transport needs to work in concert with the concentration gradient.

01:05 So ions need to move from areas of high concentration to low concentration.

01:10 If we wanted passive transport in this situation, our ions would move like so.

01:15 But we don't want that.

01:18 So passive transport is not the answer here.

01:21 Facilitated fusion is a similar idea in that it would use a channel like this to let these sodium ions pass from an area of high concentration to low concentration.

01:35 We're getting warmer here because that channel would allow the charged molecules to pass the membrane.

01:41 But that's still not what we want...

Please give Ace some feedback