Osmotic Pressure of Animal Cells
My AP Biology Thoughts
Unit 2 Cell Structure and Function
Welcome to My AP Biology Thoughts podcast, my name is Victoria and I am your host for episode #61 called Unit 2 Cell Structure and Function: Osmotic Pressure of Animal Cells. Today we will be discussing _the osmotic pressure of animal cells.
Segment 1: Introduction to Osmotic Pressure
- What is osmosis?
- The movement of a solvent/water through a semipermeable membrane from a low concentration or high water potential, where there is less solute to a higher concentration or low water potential, and it’s goal is to reach equilibrium of equal concentration of solute on the inside and out of the membrane/cell
- an example of passive transports as it does not require energy
- What is osmotic pressure?
- Osmosis creates pressure
- The pressure that must be applied to the solution side to stop fluid movement when a semipermeable membrane separates a solution from pure water.
- the pressure that would be required to stop water from diffusing through a barrier by osmosis. In other words, it refers to how hard the water would “push” to get through the barrier in order to diffuse to the other side.
- Determined by solute concentration, water will “try harder” to diffuse into an area with a high concentration of a solute, such as a salt, than into an area with a low concentration.
Segment 2: More About Osmotic Pressure of Animal Cells
- Water moves to hypertonic areas
- It can threaten the health of cells and organisms when there is too much or too little water in the extracellular environment compared to the inside of the cell.
- Animal cells lack a cell wall, and use active transport systems (especially the NA+ K+ ATPase that moves 3 NA+ out for each 2 K+ that move in) to move ions outside the cell reducing the osmotic pressure.
- Most protozoa use a special contractile mechanism. Water collects in a vesicle, and microfilaments force a contraction that squeezes water back outside the cell. This pump mechanism protects the cell from osmotic pressure
Segment 3: Connection to the Course
- How does the osmotic pressure of animals connect back to cell structure and function?
- Without osmotic pressure the animal cells would not be able to move solvent/water through a semipermeable membrane from a low concentration to high concentration, and not reach equilibrium of equal concentration of solute on the inside and out of the membrane/cell
- This will collapse its structure and both will then lead the cell to death unable to perform its necessary functions
- It is vital as the cell’s membrane is selective toward many of the solutes found in living organisms
- It determines the state/survival of the cell as well, like when it is placed in a hypotonic, isotonic, or hypertonic solutions
Thank you for listening to this episode of My AP Biology Thoughts. For more student-ran podcasts and digital content, make sure that you visit www.hvspn.com. See you next time!
Music Credits:
- “Ice Flow” Kevin MacLeod (incompetech.com)
- Licensed under Creative Commons: By Attribution 4.0 License
- http://creativecommons.org/licenses/by/4.0/
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