Question

Diffusion depends on random particle movement, so substances diffuse across cell membranes without _______?

1) Energy
2) Resistance
3) Facilitated transport
4) Active transport

Answer 1

Diffusion across cell membranes occurs through passive transport called passive diffusion, which does not require energy or transport proteins. Substances like gases can freely cross the cell membrane and diffuse from areas of higher to lower concentration.

Step-by-step explanation:

Diffusion across cell membranes occurs through passive transport, specifically passive diffusion. Passive diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration without the need for energy. This allows substances to diffuse across cell membranes without the requirement of active transport or facilitated transport, where energy or transport proteins are involved. Substances that can freely cross the hydrophobic phospholipid barrier of the cell membrane, such as gases like O2, CO2, and N2, can diffuse passively.