Diffusion Flashcards
What is the nuclear membrane and
How does the nuclear membrane relate to diffusion?
-They are semi-permeable
-good stuff in bad stuff out
-things can’t get through the membrane and need help with special door or gates made of protein
-Diffusion is an important way materials get in and out
-osmosis is how water moves across cell membrane
What is semi-permeable?
Means some stuff can go in and some stuff can’t go in
What is diffusion?
-the movement of molecules from an area of higher concentration to an area of low concentration
-bigger concentration =faster diffusion rate
-no energy spent for diffusion
What is Osmosis?
-movement of solvent molecules through a selective permeable membrane into a region of high solute concentration
-water is number one solvent
-sometimes fat is a solvent for molecules (bad)
DDT is not very soluble in water but it’s highly soluble in fat
What is Hypertonic?
-greater concentration of solute particles outside the membrane than inside
-The result is a movement of water from inside to outside the cell
-If it continues to dehydrate, shrivels and can die
-This results in plasmolysis in plant cells where the cell membrane pulls away from cell wall
- can be restored with water
What is Hypotonic?
-More solute particles in the cell that outside
-the result is a movement of water from outside to inside the cell
-This will hydrate the cell but if the pure water goes into the cell you will explode and die(cell lysis)
What is Isotonic?
-There is no concentration difference
-the result is a movement of water back and forth across the membrane
-this is what we want out cells to be in
If there is salt water should you drink it explain using diffusion
When you drink salt water, it is considered hypertonic compared to the fluids in your body. A hypertonic solution has a higher concentration of solutes, like salt, than the fluid inside your cells.
In this case, if you consume salt water, the higher concentration of salt outside your cells causes water to move out of the cells to balance the concentration. This movement occurs through osmosis, where water moves from an area of lower solute concentration (inside the cells) to an area of higher solute concentration (the salt water).
As a result, your cells lose water, leading to dehydration, which is why drinking salt water is not safe or advisable. It’s better to drink fresh water to stay hydrated!
What is Osmolarity?
The measure of concentration of solute inside or of fluid or cell
Why can’t larger organisms rely on diffusion but smaller organisms can
Because of the surface area to volume ratio. Smaller organisms like cells have high surface area to volume ratio they can rely on diffusion across their surface to exchange everything they need. Larger organisms like humans can’t rely on diffusion across their so that is why we have things like the aveoli in our lungs to exchange oxygen and remove CO2 or vili in the intestines we have vili which absorb nutrients. These examples and more increase our surface to volume ratio
