Alright, so here we have an example problem that's asking what is the main difference between active transport and facilitated diffusion? And we've got these four potential answer options down below. And so what we need to recall is that facilitated diffusion is not a type of active transport. Facilitated diffusion is a type of passive transport, which means that absolutely no energy is required for facilitated diffusion. And this is because molecules will be transported down their concentration gradients from an area of high concentration to an area of low concentration.
And so when we take a look at option a here, notice it says facilitated diffusion uses proteins, but active transport does not. And this is actually a false option, so we can cross it off our list. Now this is because both facilitated diffusion and active transport use proteins. And so, the facilitated diffusion require is, recall is facilitated by a protein. And active transport also requires a protein as well.
So both facilitated and active transport require proteins and that is not the main difference between them. Now skipping over b really quick, going to option c, notice it says active transport occurs across the plasma membrane, but facilitated diffusion does not. And once again, this is not going to be true. Of course, active transport and facilitated diffusion are both going to allow for molecules to be transported across a plasma membrane, and so they both allow for that. So that is not the main difference between the two.
And then taking a look at option d here, it says active transport and facilitated diffusion both use proteins to move substances against their concentration gradients. Now we already indicated that active transport and facilitated diffusion both use proteins, that part is true, but they don't both move substances against their concentration gradients. Only active transport moves substances against their concentration gradients from areas of low concentration to high concentration. But facilitated diffusion, which again is a type of passive transport, it does not pump molecules against their concentration gradients, it pumps molecules down their concentration gradients. So that means that option d here is also not going to be true.
And this only leaves option b here as the correct answer which says active transport uses ATP to power transport, but facilitated diffusion does not. And so we know from our last lesson video that more specifically, it's primary active transport that uses ATP directly to power transport. And facilitated diffusion, which is once again a type of passive transport, does not require any energy, so it certainly does not use ATP to power transport. And so option b here is going to be the correct answer for this example problem, and that concludes this example, so I'll see you all in our next video.