What term describes the force driving the net movement of water into or out of a cell?

What term describes the force driving the net movement of water into or out of a cell?

• A. Osmotic Pressure
• B. Isotonic
• C. Diffusion
• D. Osmosis

Answer: (A)

Osmotic pressure is the force that drives the net movement of water across a semipermeable membrane. It arises from differences in solute concentration on the two sides of the membrane, which creates a pressure that pushes water toward the side with more dissolved particles. In essence, the higher the solute concentration on one side, the greater the tendency for water to move toward that side, and osmotic pressure is that push or pull behind the water flow. Osmosis describes the actual movement of water across the membrane, isotonic describes equal solute concentrations (no net water movement), and diffusion is the general movement of particles down their concentration gradient—neither specifically names the driving force for water movement across a membrane.

Osmotic pressure is the force that drives the net movement of water across a semipermeable membrane. It arises from differences in solute concentration on the two sides of the membrane, which creates a pressure that pushes water toward the side with more dissolved particles. In essence, the higher the solute concentration on one side, the greater the tendency for water to move toward that side, and osmotic pressure is that push or pull behind the water flow.

Osmosis describes the actual movement of water across the membrane, isotonic describes equal solute concentrations (no net water movement), and diffusion is the general movement of particles down their concentration gradient—neither specifically names the driving force for water movement across a membrane.