The main constituents of the plasma membrane are ...

Question

The main constituents of the plasma membrane are                   .
a. carbohydrates and lipids;
b. proteins and phospholipids;
c. fats and carbohydrates;
d. fatty acids and nucleic acids

Accepted Answer

Hi everyone. Let's look at our next question. It says which of the following answer choices is found in the largest amount in plasma membranes. And we have our choices of glycoprotein, lipoprotein, Gallico, lipids and peptic toge likens. So let's recall um when we think about the plasma membrane of course, you know, we have a lipid BI layer and many embedded proteins. So let's look over our answer choices, says glycoprotein. Now we notice we also have a choice. See this glycoprotein um prefix glycol, A lipids in choice C glycol for something with a sugar head. And there are both proteins and lipids that have little sugar groups attached on the outside of the membrane. But if we wanted since we're talking about largest amounts, we're talking about the composition of this membrane. Um cell membranes about 50% by weight are actually protein. Because there's so many proteins embedded there. Um About 40% lipids And then only about 10% by mass carbohydrate. So these um parts with carbohydrates attached are the smallest part um when it comes to the composition of the cell membrane so we can go ahead and eliminate our glycoprotein and glycol lipids. Um those molecules with sugars attached because we know that carbohydrates are the smallest percent um when the makeup of the cell membrane. So let's look at choice B lipoprotein again, we can look at that lipoprotein prefix that tells us attached to a lipid proteins attached to lipids. Those are embedded proteins, proteins embedded in that lipid bi layer and as we saw those proteins are about 50% by weight of the composition of the membrane. So that's a good choice for our answer. Um the largest amount in plasma membranes. So we can feel pretty confident choosing Choice B. But we'll just look at choice D. To be sure. And Choice D says peptic toge likens while Pepito Glick hands are not found in plasma membranes. Um They are components of the cell wall so surrounding outside the plasma membrane of bacteria. So definitely can rule out pepto like hounds as they're not even found in plasma membranes. So, our final answer here, choice be lipoprotein. As the answer choice. Found in the largest amount in plasma membranes. See you in our next video.

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