osmosis

What is osmosis?

Passive transport of WATER across a semipermeable membrane. Net movement is toward the side with more solute.

Hypertonic, isotonic, hypotonic?

Hypertonic = lots of solute (tastes super sugary). Isotonic = equal to the other side. Hypotonic = little solute (tastes diluted). They compare two solutions.

Cell in a hypertonic solution?

Outside has more solute, so water leaves the cell and the cell shrivels.

Cell in a hypotonic solution?

Outside has less solute, so water rushes in and the cell swells (may burst).

Does water move in only one direction?

No. Water moves both ways all the time. We track the NET movement, which goes toward more solute.

U-tube: A = 0.4 M glucose + 0.5 M NaCl. B = 0.8 M glucose + 0.4 M NaCl. Which way does water go?

Toward side B. B has more dissolved solute (0.8 vs 0.4 glucose; 1.2 vs 0.9 total), so B is hypertonic and A is hypotonic.