What is the effect of increased membrane thickness on gas diffusion?

• A. It facilitates easier diffusion.
• B. It has no effect on diffusion.
• C. It impedes diffusion.
• D. It increases gas exchange efficiency.

Answer: (C)

Increased membrane thickness impedes the diffusion of gases. This relationship is rooted in Fick's law of diffusion, which states that the rate of diffusion of a gas across a membrane is inversely proportional to the thickness of that membrane. As the membrane becomes thicker, the distance that gases must travel increases, leading to a decrease in the rate of diffusion. Essentially, thicker membranes create a greater barrier for the molecules to permeate, which slows down the movement of oxygen and carbon dioxide during gas exchange in the lungs or other biological systems. Consequently, the efficiency of gas exchange is compromised, which can have significant physiological implications, especially in respiratory conditions or any situations where gas exchange is critical.