Osmosis

Osmosis

Net movement of water from a dilute solution to a concentrated solution

Hypertonic

When there is a higher concentration of solute inside a cell; water moves in.

Hypotonic

When there is a higher concentration of solute outside the cell; water moves out.

Isotonic

When there is the same concentration of solute in and out the cell; no osmosis occurs

Turgid cell

When a cell takes in too much water and becomes swollen.

RBC turgidity

If osmosis occurred, (in a the RBCs would become too turgid since they don't have anything for their cell membrane to push against. This then leads the cell to rupture and burst.

How RBCs avoid rupturing

They maintain a constant concentration in and outside the cell (maintains an isotonic concentration).

Plant cell osmosis

Plant cells are surrounded by cell walls that push against the cell membrane, which decreases pressure levels and stops extra water from entering so the cell does not rupture.

Osmosis vs. Diffusion

Osmosis - water crosses a membrane to lower the concentration gradient between solutions.

Diffusion - substances (gases) going from higher to lower concentration.

Plasmolysis (plant cells)

In a hypertonic solution, when plant cells shrivel and the cell membrane shrinks from the cell wall.