Membranes Osmosis

Question 1

What is osmosis?

Answer 1

Osmosis is the movement of water molecules across a partially permeable membrane form a high water potential to a Low water potential

Question 2

What is meant by a high water potential?

Answer 2

If something has a high water potential then it has a high concentration of water molecules.

Question 3

What is meant by something having a low water potential?

Answer 3

it has a low concentration of water molecules.

Question 4

What is the water potential of pure water?

Answer 4

0

Question 5

If the water potential of something is highly negative what can be said about that solution?

Answer 5

Solution is very concentrated

Question 6

If two solutions have the same water potential what can be said about the solutions?

Answer 6

Theyre isotonic

Question 7

If a cell is put in an isotonic solution what will occur?

Answer 7

no osmosis will occur as there will be no concentration gradient.

Question 8

If a solution has a higher water potential than the cell which is placed with in it , the solution can be referred to as?

Answer 8

Hypotonic

Question 9

If a solution has a lower water potential than the cell which is placed within it it can be referred to as?

Answer 9

Hypertonic

Question 10

If a cell is placed in a hypotonic collation what happens?

Answer 10

the solution has a higher water potential than the cell itself hence water moves into the cell down the water potential gradient to bring the concentrations to an equilibrium.

Question 11

If a cell is placed in a hypertonic solution what happens?

Answer 11

the water potential of the solution is lower than that of the water potential in the cell , water thus moves out from the cell into the solution to even the water potential gradient until an equilibrium is reached.

Question 12

Which 3 factors affect the rate of osmosis?

Answer 12

The water potential gradient
The thickness of the exchange surface
The surface area of the exchange surface

Question 13

How does the water potential gradient affect the rate of osmosis?

Answer 13

The higher the water potential gradient, the faster the rate of osmosis. As osmosis takes place, the difference in water potential on either side of the membrane decreases, so the rate of osmosis levels off over time.

Question 14

How does the thickness of the exchange surface affect the rate of osmosis?

Answer 14

The thinner the exchange surface, the faster the rate of osmosis.

Question 15

How does the surface area of the exchange surface affect the rate of osmosis?

Answer 15

The greater the surface area the greater the rate of Osmosis.

Question 16

Osmosis can cause a plant cell to become flaccid , under what circumstances would this happen?

Answer 16

A plant cell becomes flaccid when it looses water , water is lost from a plant cell when it is put in a hypertonic solution (absolution which has a lower water potential than the cell itself).