In this video, we're going to distinguish between passive and active transport. And so really there are 2 general types of molecular transport or transport of very, very small molecules across biological membranes. And those two general types of molecular transport are passive transport and active transport. Now passive transport requires absolutely no energy whatsoever, and that's because passive transport transports molecules passively from an area of high concentration down to an area of low concentration. Now active transport, on the other hand, does require energy unlike passive transport, which does not require energy, and that's because active transport will transport molecules actively from an area of low concentration to an area of high concentration.
And so let's take a look at our example down below to further distinguish between passive and active membrane transport. And so over here, notice that we're showing you a little snippet of the map of the lesson from our previous lesson video, and we're focusing in on molecular transport of very very small molecules, and they can be transported across the membrane using one of these two types, either passive transport, which requires absolutely no energy whatsoever, or the second type is active transport, where energy is required. Now, in these images, notice that number 1 corresponds with passive transport. And notice that with passive transport, here we're showing you the biological membrane, and, notice that these molecules here are in high concentration on this side of the membrane, so we can label it as high concentration over here. And on this side of the membrane over here, notice there's quite a low concentration.
And so with passive transport, molecules are going to be transported from an area of high concentration to an area of low concentration. So the high concentration is here, low concentration is here, so it will be transported in this direction, the direction of the arrow that you see right here. And so passive is going to represent a process where absolutely no energy is required. Now on the other hand, over here on the right hand side, we're showing you, of course, active transport. And notice that with active transport, it's going to be transporting molecules from an area of low concentration towards an area of high concentration.
So here we're focusing in on these purplish molecules and notice, up above here we have an area of high concentration of the purple molecules and down below, we have an area of low concentration of the purple molecule. So we can label this as low concentration. And so notice that the direction of movement is going towards the area of higher concentration, from low concentration towards high concentration, and that is what makes this active transport. And active transport is going to require energy in the form of ATP. And recall, ATP is this high-energy molecule that cells utilize for energy. And so you can think the a in active transport is for the a in ATP, and that means that energy is required.
So active means energy. And so this here concludes our, introduction to the difference between passive and active transport, and moving forward we'll be able to talk more and more about the differences between the 2 and also different types of passive transport and different types of active transport as well. So I'll see you guys in our next video.