#AP Biology: Osmosis & Water Potential - The Night Before 🚀

Hey! Let's get you prepped for the exam. This guide is designed to be super clear and easy to use, especially when time is tight. We'll cover everything you need to know about tonicity, osmosis, and water potential, with a focus on what's most likely to show up on the test.

#Tonicity: Cell's Water Balance ⚖️

Understanding how water moves in and out of cells is crucial. It's all about the concentration of solutes (stuff dissolved in water) inside versus outside the cell. Remember, water always moves from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration).

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• Hypotonic Solution:

  • Less solute outside the cell than inside. 💧
  • Water rushes into the cell. Think HYPO-HIPPO 🦛 – cells swell up like a hippo!

• Hypertonic Solution:

  • More solute outside the cell than inside. 🏃‍♀️
  • Water rushes out of the cell. Think HYPER – when you're hyper, you run outside and lose water!

• Isotonic Solution:

  • Equal solute concentration inside and outside the cell.
  • No net water movement. Cell stays the same size. 😌

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Animal Cell:

Image courtesy of Wikipedia

Plant Cell:

Image courtesy of Wikipedia

#Osmosis: Water's Journey Across Membranes 🌊

Osmosis is the specific term for water moving across a semi-permeable membrane. It's driven by the need to equalize solute concentrations. Think of it as water trying to dilute the side with more "stuff.