So now that we know from our last lesson video that there are 2 types of active transport, primary active transport and secondary active transport. In this video, we're going to focus on primary active transport. And so Primary Active Transport is an ATP-driven process that transports molecules against their concentration gradients from areas of low concentration to areas of high concentration, and that is why it requires energy in the form of ATP. Now once again, primary active transport is going to be driven directly by energy derived from ATP hydrolysis, and really this is the biggest difference between primary and secondary active transport. Primary active transport is directly linked to ATP hydrolysis, but secondary active transport is not as we'll learn, moving forward talking about secondary active transport in another video.
Now primary active transport can be used to generate and maintain very important concentration gradients for survival. And so we'll be able to talk about a very important primary active transport example in our next lesson video. But for now let's take a look at the image that we have down below which is showing us primary active transport. And so notice here we have a membrane, here in the middle, and notice that primary active transport is going to require the use of a membrane protein, and that membrane protein is going to use ATP directly, as we indicated above, in order to transport molecules against their concentration gradient from an area of low concentration over here on this side of the membrane because there are only 3 molecules, and it's still pumping them toward an area of higher concentration, and so you can see there is a much higher concentration over here. And so because this purple molecule is being pumped against its concentration gradient, it requires active transport.
And because ATP is used directly, it is a form of primary active transport. And so ATP here is really providing the energy that is required to pump the molecule across the membrane. And so this here concludes our introduction to primary active transport, and we'll be able to see a very specific example of primary active transport in our next lesson video when we talk about the sodium-potassium pump. So I'll see you guys in that video.