Question

look at the cell membrane.
diagram of cell membrane with labels: lipid molecules, protein molecules
the diagram reveals that lipids and proteins are both parts of cell membranes. they have different functions because lipids work to
a. remove nucleic acids from the cell membrane, and proteins work to hold the cell membrane together.

b. hold the cell membrane together, and proteins move chemicals across the cell membrane.

c. stiffen the cell membrane, and proteins create fibers that attach to the ends of the lipids.

d. move chemicals across the cell membrane, and proteins work to store water in the cell membrane.

Explanation:

To solve this, we analyze the functions of lipids and proteins in the cell membrane:

• Lipids (phospholipids) form a bilayer that holds the cell membrane together (provides structure).
• Proteins in the membrane (e.g., transport proteins) move chemicals (molecules/ions) across the cell membrane (facilitate transport).

Now, evaluate the options:

• Option A: Incorrect. Lipids do not remove nucleic acids, and proteins do not hold the membrane together (lipids do that).
• Option B: Correct. Matches the known functions of lipids (hold membrane) and proteins (transport chemicals).
• Option C: Incorrect. Lipids do not stiffen the membrane, and proteins do not create fibers attached to lipids.
• Option D: Incorrect. Lipids do not move chemicals, and proteins do not store water in the membrane.

Answer:

B. hold the cell membrane together, and proteins move chemicals across the cell membrane.