Which factor would increase the rate of diffusion across a cell membrane?

• A. Increasing the size of the diffusing molecules
• B. Decreasing the surface area of the membrane
• C. Increasing the temperature
• D. Decreasing the concentration gradient

Answer: (C)

Verified step by step guidance

1. Understand the concept of diffusion: Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. It is driven by the concentration gradient and does not require energy.
2. Identify factors affecting diffusion rate: The rate of diffusion can be influenced by several factors, including the size of the molecules, the surface area of the membrane, the temperature, and the concentration gradient.
3. Analyze the effect of temperature: Increasing the temperature generally increases the kinetic energy of molecules, causing them to move faster. This increased movement can enhance the rate of diffusion across the cell membrane.
4. Consider the concentration gradient: A steeper concentration gradient (greater difference in concentration between two areas) can increase the rate of diffusion, as molecules will move more rapidly from high to low concentration.
5. Evaluate the impact of molecule size and membrane surface area: Larger molecules diffuse more slowly due to their size, and a smaller surface area of the membrane can limit the space available for diffusion, both of which would decrease the rate of diffusion.