Which of the following statements about transport across plasma membranes of cells is correct?

Question

Quizplus · Accepted Answer

Facilitated diffusion transport systems are bidirectional, meaning that molecules can move in both directions depending on the concentration gradient. The net direction of transport will depend on the concentration gradient, with molecules moving from higher to lower concentration until equilibrium is reached. This is in contrast to active transport systems, which are unidirectional and require energy to move molecules against their concentration gradient. Option B is incorrect because while some small compounds can diffuse across membranes, others require transport systems. Option C is incorrect because some transport systems can transport molecules in both directions, as in the case of facilitated diffusion. Option D is incorrect because hydrophobic molecules can cross membranes more easily than hydrophilic molecules due to their ability to dissolve in the hydrophobic lipid bilayer of the membrane. Option E is incorrect because some ions, such as chloride and bicarbonate, can cross membranes quickly through specialized ion channels or transporters.

Which of the Following Statements About Transport Across Plasma Membranes