AP Biology / Unit 2: Cell Structure and Function
2.7 Tonicity and Osmoregulation
Notes
Water moves toward higher solute concentration (lower water potential).
- Hypertonic solution: cell loses water. Hypotonic: cell gains water. Isotonic: no net change.
- Water potential: $\Psi=\Psi_s+\Psi_p$, with $\Psi_s=-iCRT$.
Practice
A red blood cell in pure water will:
Water is hypotonic to the cell.
Water moves from:
Down the water potential gradient.
Plant cells in hypotonic solution become:
The wall stops them from bursting.
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