What Do You Mean by Endosmosis?
Endosmosis is the movement of water into a cell. This happens when a cell is placed in a hypotonic solution – a solution with a lower concentration of solutes (like salt) compared to the inside of the cell. The water moves across the cell membrane, from an area of high water concentration (the hypotonic solution) to an area of low water concentration (inside the cell), causing the cell to swell.
Think of it like this: imagine a raisin placed in water. The raisin (representing the cell) has a lower water concentration than the surrounding water. Water will move into the raisin, causing it to plump up. This is endosmosis in action.
Key Characteristics of Endosmosis:
- Movement of Water: The primary focus is on the net movement of water molecules.
- Hypotonic Solution: It occurs when the cell is surrounded by a solution with a lower solute concentration.
- Semi-Permeable Membrane: Water moves across a selectively permeable membrane, allowing water to pass but restricting the movement of solutes.
- Cell Swelling: The influx of water leads to an increase in cell volume. In plant cells, this creates turgor pressure, which helps maintain the plant's structure.
Examples of Endosmosis:
- Root Hair Absorption: Plants absorb water from the soil through their root hairs via endosmosis.
- Water Uptake by Cells: Many single-celled organisms rely on endosmosis to regulate their water balance.
Contrasting Endosmosis with Exosmosis:
Endosmosis is the opposite of exosmosis, where water moves out of a cell into a hypertonic solution (a solution with a higher solute concentration). In exosmosis, the cell shrinks or plasmolysis occurs.
(Reference: Multiple sources confirm the definition and explanation of endosmosis as the movement of water into a cell in a hypotonic solution. The provided snippets from various websites and educational resources strongly support this.)
