Alright. So let's run through our example. Our example reads, Terry was injected with a poison that blocks the sodium-potassium pump. With the sodium-potassium pump blocked, what will happen to the concentration of potassium inside the cell? All right.

So let's just kind of draw this out so that we remember what's going on. In a cell, we have higher concentrations of potassium inside and higher concentrations of sodium on the outside, right, which means that potassium, following its concentration gradient, wants to leak out of the cell and sodium wants to come into the cell. And our pump is working to kick that sodium back out, right, and bring that potassium back in. Okay? So that's what's going on.

And now that that's kind of fresh in our heads, let's think through these answer choices. So a reads that if the pump was blocked, the concentration of potassium inside the cell will increase. And that can't be right. Because if we just have potassium leaking out and there's nothing replacing it, it's definitely not going to increase. So a is out.

B reads the concentration of potassium will decrease, and that is correct. So if potassium is just leaking out and there's nothing replacing it, it's going to decrease over time. So let's just really quickly go through c to make sure that we understand why it's not correct. So c reads that the concentration of potassium will be unaffected, and that's just not true because, like we just talked about, potassium wants to be leaking out.

And now there's no pump replacing it. And so the concentration is certainly being affected in that it is decreasing. Right? So c is incorrect as well. Right?

So our answer is b, the concentration of potassium will decrease. And there you go.