Question

select the true statements. carbon dioxide crosses the cell membrane in both directions. carbon dioxide can move across cell membranes via simple diffusion because it is small and nonpolar. simple diffusion is the unassisted diffusion of molecules directly through the phospholipid bilayer. diffusion is a form of active transport.

Explanation:

• Carbon dioxide crosses the cell membrane in both directions as it moves down its concentration gradient.
• Carbon dioxide is small and nonpolar, so it can move across cell membranes via simple diffusion.
• Simple diffusion is indeed the unassisted diffusion of molecules directly through the phospholipid bilayer.
• Diffusion is a form of passive transport (not active transport) as it does not require energy input.

Answer:

• Carbon dioxide crosses the cell membrane in both directions.
• Carbon dioxide can move across cell membranes via simple diffusion because it is small and nonpolar.
• Simple diffusion is the unassisted diffusion of molecules directly through the phospholipid bilayer.