Diffusion and Osmosis Lab Flashcards
Diffusion
The net movement of one substance from an area of higher concentration to an area of lower concentration.
Osmosis
Net diffusion of water across a selectively permeable membrane.
Dialysis*
Can be used to selectively separate solutes from a solution.
It involves the diffusion of solutes through a selectively permeable membrane.
Selective Permeability
Permits the free passage of some molecules and restricts the passage of others.
Isotonic Solution
Solutes outside a cell are in equilibrium with solutes inside a cells.
Hypotonic Solution
Solutes outside a cell are lower concentration than solutes inside a cell. Thus water enters cell.
Hypertonic Solution
Solutes outside a cell are higher concentration than solutes inside a cell. Thus water leaves the cell.
What effect does molecular size have on diffusion rate?
Smaller molecules diffuse faster. Larger molecules diffuse slower.
What determined the permeability of the dialysis tubing?
Pore size
What do you call the difference between an area of high concentration and an area of low concentration?
Concentration Gradient
Which dye molecules are larger? MB or PP
Why?
Methylene Blue.
Slow diffusion rate.
Isotonicity
Cell not affected
Hypertonicity
Water leaving the cell.
Cell is shrinking and dehydrating.
Hypotonicity
Water going into the cell.
Cell is swelling and may rupture.
Osmosis resulted in net outflow of water from the dialysis bag.
Lost water from the bag into the beaker.
Weighed bag after one hour and it lost 7% weight.
Solution is hypertonic–40% Glucose.
Cell is hypotonic 0% Glucose.
Osmosis caused the flow of water into the dialysis bag.
Bag swelled because it gained water from the beaker.
Bag increased in weight by 17%
Solution is Hypotonic–0% glucose
Cell is Hypertonic–40% glucose
Important figure.
Which is the hypotonic solution in the figure?
The ECF–extracellular fluid
Important figure.
Which solutes were found in the ECF after one hour?
NaCl
Glucose
Important figure.
Which way did the water flow in this experiment.
Into the cell.
Diffusion means the solutes in the _____ concentration region will move into the region with _____ concentration.
higher
lower
True or False
When solutes move through a selectively permeable membrane it is called dialysis.
True.
Osmosis is the diffusion of _____ through a selectively permeable membrane.
- Glucose
- NaCl
- Water
- Water
