Question

multiple select question
select all that apply
select factors that determine if a substance is permeable through the plasma membrane.

☐ solubility
☐ size
☐ temperature
☐ electrical charge
☐ presence of carrier protein

Explanation:

• Solubility: The plasma membrane is a lipid - bilayer, so substances with lipid - solubility (like non - polar molecules) are more likely to be permeable. Hydrophobic substances can dissolve in the lipid part of the membrane.
• Size: Smaller molecules (e.g., oxygen, carbon dioxide) can pass through the membrane more easily than larger molecules. The membrane has small pores or spaces that restrict the passage of large molecules.
• Electrical Charge: Charged molecules (ions) have difficulty passing through the non - polar lipid bilayer. The hydrophobic interior of the membrane repels charged species.
• Presence of carrier protein: Carrier proteins can facilitate the transport of substances that are otherwise impermeable (e.g., glucose, amino acids) by binding to them and undergoing a conformational change to move the substance across the membrane.
• Temperature: Temperature affects the fluidity of the plasma membrane. Higher temperature increases membrane fluidity, which can affect the rate of diffusion of substances, but it is not a primary factor that determines if a substance is permeable (i.e., whether it can pass at all) in the same way as the other factors. So temperature is not a factor that determines permeability (whether a substance can pass) but rather the rate of passage.

Answer:

A. Solubility, B. Size, D. Electrical Charge, E. Presence of carrier protein