What process describes the movement of water across a semi-permeable membrane?

The movement of water across a semi-permeable membrane is specifically referred to as osmosis. This process involves the passive movement of water molecules from an area of lower solute concentration to an area of higher solute concentration, aiming to equalize solute concentrations on both sides of the membrane. The semi-permeable nature of the membrane allows water molecules to pass through while blocking larger solute particles, facilitating this natural balancing act.

In osmosis, no energy is required for the movement of water, which distinguishes it from processes like active transport, where energy is needed to move substances against their concentration gradient. Understanding osmosis is crucial in a biomedicine context, as it plays an essential role in cellular functions, fluid balance, and overall homeostasis in living organisms.