Osmosis Note Flashcards

Describe Osmosis

The movement of water from an area of high concentration to low concentration depending on the solute concentration

• passive transport

• can be both simple and facilitated (aquaporins)

The left side of the jar has 5% NaCI and the right has 15% NaCI. Why would water move towards the right side instead of the left over time?

Because there is a high concentration of water on the left and a low concentration of water on the right, the water will diffuse through the membrane from a high to low concentration

• high concentration of water = low solute concentration

• low concentration of water = high solute concentration

Osmotic Particles

the dissolved solutes that are separated from a solvent (typically water) by a semipermeable membrane

• ex. salts, sugars, and ions

Hypertonic Solutions

an external solution with a higher concentration of solutes and a lower concentration of H2O compared to the inside of a cell

• animal cells in a hypertonic solution will shrivel, causing it to shrink and die

• plant cells in a hypertonic solution will also shrink and will loose its rigidity, causing it to wilt (plasmolysed)

Hypotonic Solution

an external solution with a lower concentration of solutes and a higher concentration of H2O compared to the inside of a cell

• animal cells in a hypotonic solution will swell up, causing it to burst and die

• plant cells in a hypotonic solution will also swell up, but will not burst due to the cell wall preventing that to happen (turgid)

Isotonic Solution

an external solution with the same concentration of solutes and H2O compared as the inside of a cell

• both animal and plant cells will remain the same

What is always true about the movement of water?

H2O will always move from a hypotonic solution to a hypertonic solution

Plasmolysed/Flaccid Plant Cell

a plant cell that is in a hypertonic solution, causing the membrane to shrink and pull away from the rigid cell wall due to excessive water loss

• causes it to wilt

Turgid Plant Cell

a plant cell that is in a hypotonic solution, causing it to be firm and swollen with water as the high turgor pressure pushes outwards against its cell wall

Flaccid Plant Cell

a plant cell that is in a isotonic solution, causing the water to move in and out of the cell at equal rates. This results in a lack of net water movement and the loss of turgor pressure against the cell wall, making the cell limp.