Diffusion and Osmosis Lab

Question 1

Diffusion

Answer 1

The net movement of one substance from an area of higher concentration to an area of lower concentration.

Question 2

Osmosis

Answer 2

Net diffusion of water across a selectively permeable membrane.

Question 3

Dialysis*

Answer 3

Can be used to selectively separate solutes from a solution.

It involves the diffusion of solutes through a selectively permeable membrane.

Question 4

Selective Permeability

Answer 4

Permits the free passage of some molecules and restricts the passage of others.

Question 5

Isotonic Solution

Answer 5

Solutes outside a cell are in equilibrium with solutes inside a cells.

Question 6

Hypotonic Solution

Answer 6

Solutes outside a cell are lower concentration than solutes inside a cell. Thus water enters cell.

Question 7

Hypertonic Solution

Answer 7

Solutes outside a cell are higher concentration than solutes inside a cell. Thus water leaves the cell.

Question 8

What effect does molecular size have on diffusion rate?

Answer 8

Smaller molecules diffuse faster. Larger molecules diffuse slower.

Question 9

What determined the permeability of the dialysis tubing?

Answer 9

Pore size

Question 10

What do you call the difference between an area of high concentration and an area of low concentration?

Answer 10

Concentration Gradient

Question 11

Which dye molecules are larger? MB or PP

Why?

Answer 11

Methylene Blue.

Slow diffusion rate.

Question 12

Answer 12

Isotonicity

Cell not affected

Question 13

Answer 13

Hypertonicity

Water leaving the cell.

Cell is shrinking and dehydrating.

Question 14

Answer 14

Hypotonicity

Water going into the cell.

Cell is swelling and may rupture.

Question 15

Answer 15

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.

Question 16

Answer 16

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

Question 17

Important figure.

Which is the hypotonic solution in the figure?

Answer 17

The ECF–extracellular fluid

Question 18

Important figure.

Which solutes were found in the ECF after one hour?

Answer 18

NaCl

Glucose

Question 19

Important figure.

Which way did the water flow in this experiment.

Answer 19

Into the cell.

Question 20

Diffusion means the solutes in the _____ concentration region will move into the region with _____ concentration.

Answer 20

higher

lower

Question 21

True or False

When solutes move through a selectively permeable membrane it is called dialysis.

Answer 21

True.

Question 22

Osmosis is the diffusion of _____ through a selectively permeable membrane.

1. Glucose
2. NaCl
3. Water

Answer 22

3. Water