Osmosis Flashcards
Define Osmosis
Osmosis is the movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration.
What is a partially permeable membrane?
A membrane with very small holes in it.
What molecules can and can’t fit through the partially permeable membrane?
Only tiny molecules such as water can pass through, but molecules such as sucrose can’t.
Why can’t molecules such as sucrose pass through the partially permeable membrane?
Because they are too big to pass through the tiny holes in the membrane.
When osmosis occurs,in what direction do the water molecules pass through the membrane
The water molecules pass both ways through the membrane during osmosis?
Why do the water molecules pass both ways during osmosis?
Because water molecules move about randomly all the time.
What does a net flow mean?
A net flow is when there is more water molecules moving to one side of the membrane than the other.
Why is there a net flow?
Because more water molecules move into the region where there is fewer water molecules so there is a steady net flow.
What does dilute mean?
Dilute means when the solution gets weaker because more water molecules are added so the solution is less concentrated.
How does water move into cells?
By osmosis.
What surrounds the cells in our body?
Tissue fluid.
What is tissue fluid made up of?
Water, oxygen and glucose.
Where is the tissue fluid from?
The tissue fluid is squeezed from the blood capillaries.
What’s the job of the tissue fluid?
To supply the cells with everything they need.
What will happen if the cell is short of water?
The solution inside the cell will become quite concentrated. However, the tissue fluid solution outside the cell will be more dilute and so the water will move into the cell by osmosis.
