The Diffusion Of Free Water Essay
Cells are the basis of all life forms. Cells are separated from each other and the surrounding environments by the cell membrane (and cell wall in plants). The cell membrane keeps together the cell’s organelles (the nucleus and mitochondria for example) by forming a semi-permeable barrier, allowing specific molecules to enter and leave the cell. This movement of substances entering and leaving the cell is called active transport (when the movement uses energy) or passive transport (when the movement uses no energy).
Passive transport is the diffusion of a substance across a membrane with no energy investment.
Diffusion is the movement of molecules of any substance so that they spread out evenly in the available space.
The diffusion of free water across a selectively permeable membrane, whether artificial or cellular, is called Osmosis.
The movement of water across the cell membrane depends on the concentration of solutes on both sides of the cell membrane. When water moves out of the cell, the cell will shrink, and when water moves into the cell, it will swell and possibly burst.
Water is isotonic and moves freely across the cell membrane. Hypertonic solutions have a higher amount of solutes, while Hypotonic solutions have lower amounts of solutes.
A cell immersed in plain water tends to swell as water diffuses in from the hypotonic solution. A cell shrivels when placed in a solution of high salt concentration. The cell loses water, which moves outside to the…