Alright. So here we have an example problem that's asking, membranes are a fluid mosaic of what major components? And we've got these 4 potential answer options down below. And so of course we know from our last lesson video that phospholipids make up the major component of biological membranes, and so we would expect that one of the major components listed for the answer should be phospholipids. But when we take a look at answer option a, notice that it has a lot of molecules listed but no phospholipids, which is the major component, and so option a is not going to be the best answer option here.

And notice that all of the other answer options do mention phospholipids, so very nice. Now we have the major component considered in those three answer options. Now what we need to realize next is that nucleic acids are not going to be a major component of biological membranes. In fact, they're not really a component of biological membranes at all. And so for that reason, we can go ahead and eliminate answer option c.

Now when we take a look at option b and option d, what you'll notice is the real difference between them is cholesterol or glucose. Now glucose, we did not mention is going to be a major component of biological membranes, and in fact, it turns out that glucose is not a major component of biological membranes. But we did mention in our last lesson video that cholesterol is a major component of animal cell membranes or biological membranes. And so b here is going to be the correct answer. Phospholipids, proteins, and cholesterol are major components of cell membranes.

And so we can go ahead and indicate that b here is the correct answer for this example. And if we go back up to our image from our previous lesson video, you can see that proteins are certainly in, a major component of the membrane. Cholesterol is also a major component of the membrane. And once again, these little structures that we see here with the two tails, these are all phospholipids, and so they're the major component of biological membranes. So once again, b here is the correct answer to this example and that concludes this example so I'll see you all in our next video.