Question

multiple choice question
the plasma membrane is best described as ______.

• a phospholipid bilayer embedded with cholesterol and proteins
• a layer of triglycerides with attached carbohydrates and proteins
• a cholesterol bilayer embedded with proteins and phospholipids
• a layer of phospholipids with attached carbohydrates and proteins
• a protein bilayer embedded with cholesterol and triglycerides

Explanation:

The plasma membrane's structure is a phospholipid bilayer (two layers of phospholipids) with cholesterol (for stability) and proteins (for various functions like transport, signaling) embedded in it. Triglycerides are not a main component of the plasma membrane, so options with triglycerides are incorrect. Cholesterol is not the main bilayer component (phospholipids are), so the option with cholesterol bilayer is wrong. A single layer of phospholipids is incorrect (it's a bilayer), and protein bilayer is incorrect as the main bilayer is phospholipid. So the correct description is a phospholipid bilayer embedded with cholesterol and proteins.

Answer:

a phospholipid bilayer embedded with cholesterol and proteins