Question : what is the realtionship between the two terms?
1.) concentration gradient, diffusion
2.) osmosis, turgor pressure
3.) hypertonic, plasmolysis
serious answers only please, it is very appreciated
Answer : Diffusion is usually across a concentration gradient. So for example, someone peels an orange at the front of a room, you don't all smell it exactly at the same time. The smell will diffuse through air from highest to lowest concentration (across the gradient).
Osmosis and turgor pressure - deals with water moving in and out of cells. The more water moves into, say, a plant cell (since it has a cell wall and won't rupture) the higher the turgor pressure as a result.
Hypertonic/Plasmolysis - in a hypertonic solution, a plant (or animal) cell will have a higher concentration of solute in the cell than in the surrounding environment, so water (moving across the concentration gradient) will want to move OUT of the cell, causing the contents to shrivel up, which = plasmolysis
Question : Why don't they do this when immersed in distilled water?
Answer : onions are plants, so they have water in them. when you put the onion into salt water, you are creating a hypertonic environment for it - there is more water in the onion than in the salt water, therefore there is a concentration gradient. so, water will move out of the onion by osmosis in order to establish an equilibrium - the water concentrations must be equal, or the water will travel from an area of high concentration to an area of low concentration, in order to balance the concentration gradient.
thus, when water travels out of the onions, the cells shrivel ->plasmolysis
Question : What effect does the concentrated sugar have on the inside of the cell? I know that chloroplasts etc collect in the middle of the cell but what is the process?
Answer : Plasmolysis occurs as the volume of the cell decreases due to water leaving the cell by osmosis resulting in the cell membrane pulling away from the cell wall.