CHAPTER 3

Movement of Substances across the Plasma

Membrane in Everyday Life

Hypotonic, isotonic and hypertonic solution

A B

C

Types of solution

Hypotonic Hypertonic Isotonic A solution in which the concentration of solute outside the cell is lower than the concentration of solute inside the cell

A solution in which the concentration of solute outside the cell is higher than the concentration of solute inside the cell

A solution in which the concentration of solute outside the cell is equal with the concentration of solute inside the cell

The effects of hypotonic, hypertonic and isotonic solutions on animal and plant

cells

Group DiscussionGroup 1 = discuss the effect of

hypotonic solution on animal and plant cell.

Group 2 = discuss the effect of isotonic solution on animal and plant cell.

Group 3 = discuss the effect of hypertonic solution on animal and plant cell.

Hypotonic solution

Animal cellA solution in which the concentration of solute outside the cell is lower than the concentration of solute inside the cellwater from the surrounding enters the cell by osmosis

Hypotonic solution

Animal cellCell swell up and Cell swell up and burstburst

HAEMOLYSIS HAEMOLYSIS = = the bursting the bursting of red blood of red blood cellcell

Bursting of the Bursting of the cell = LYSIScell = LYSIS

Hypotonic solution

Plant cell

water from the surrounding diffuses water from the surrounding diffuses into large central vacuole by osmosisinto large central vacuole by osmosis

A solution in which the concentration of solute outside the cell is lower than the concentration of solute inside the cell

Hypotonic solution

Plant cellLarge central vacoule expand & swell upPlasma membrane are pushed against cell wall. In this condition, the cell is said to be turgid

Hypotonic solution

Swelling of the cell creates turgor pressure – support & maintain shape of cell

Turgidity – cause guard cell to swell – stomata open for photosynthesis

Isotonic solution

Animal cell

Water molecules move into and out of a cell via osmosis at the same rate and the cell retains its normal shape

A solution in which the concentration of solute outside the cell is equal with the concentration of solute inside the cell

Isotonic solution

Plant cell

Water molecules move into and out of a cell via osmosis at the same rate and the cell retains its normal shape

A solution in which the concentration of solute outside the cell is equal with the concentration of solute inside the cell

Animal cell

Hypertonic solution

water from inside the water from inside the cell move out of the cell move out of the cell by osmosiscell by osmosis

A solution in which the concentration of solute outside the cell is higher than the concentration of solute inside the cell

Animal cell

Hypertonic solution

cell loses cell loses water and water and shrinksshrinks

Shrinking of the Shrinking of the cell is known as cell is known as crenationcrenation

Hypertonic solution

Plant cellA solution in which A solution in which

the concentration of the concentration of solute outside the solute outside the cell is higher than cell is higher than the concentration of the concentration of solute inside the cellsolute inside the cell

Water diffuses out Water diffuses out of the large central of the large central vacoule by osmosisvacoule by osmosis

Hypertonic solutionPlant

cell Vacuole loses water.Vacuole loses water.

Vacuole & Vacuole & cytoplasm shrink & cytoplasm shrink & plasma membrane plasma membrane pulls away from cell pulls away from cell wallwallShrinking of Shrinking of cytoplasm is called cytoplasm is called plasmolysisplasmolysisThe cell becomes The cell becomes flaccid.flaccid.

Hypertonic solution

Flaccidity – cause the leaves Flaccidity – cause the leaves become limp & stem to droop – become limp & stem to droop – wilting occurs.wilting occurs.

If plasmolysis prolonged, it can lead to the death of the cell.

However, a plasmolysed cell can becomes turgid again ---HOW??

By immersing the cell in a hypotonic solution.

Water is taken up by osmosis & the flaccid cell become fully turgid again.

Cell is said to have undergone deplasmolysis

activity

My GrOuP VS YoUr GrOuPWHOSE GROUP IS THE BEST

Explain how cell becomes turgid?

$4000

When plant cell is placed in hypotonic solution,

Water enters into the large central vacuole by osmosis

Large central vacoule expand & swell up

Plasma membrane are pushed against cell wall. In this condition, the cell is said to be turgid

This phenomenon only happens in a plant cell when it is placed in a hypertonic solution. Explain what happen to the cell.

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When plant cell is placed in hypertonic solution, the solute concentration outside the cell is higher than solute concentration in the cell.Water diffuses out of the cell by osmosis.

Vacuole and cytoplasm shrink and plasma membrane are pull away from the cell wall.

Cell undergoes plasmolysis and become flaccid.

Describe the process involved in the diagram above.

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In a hypotonic solution, the solute concentration outside the RBC is lower than the solute concentration in RBC.

Water enters the RBC by osmosis.

RBC swell up and burst.

Explain what is deplasmolysis?

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When a plasmolysed/flaccid plant cell is placed in hypotonic solution,

Water enter the plant cell,Because the solute concentration outside the cell is lower than solute concentration inside the cell.

The flaccid cell gain water and become turgid again.

The cell is said have undergone deplasmolysis.

Explain what is deplasmolysis?

Assessment

1. Plant cells show turgor pressure when

A. The cells are losing water from their vacuoles

B. The vacuoles are filled with water

C. Water is being utilised during photosynthesis

D. Water is being evaporated from the leaves

2. Human red blood cells are placed in distilled water. In which direction does water move and what is the effect on the cells?

Movement of water Effect on cell

A Into the cell Slight increase in size

B Into the cell Cells burst

C Out of the cell Slight decrease in size

D Out of the cell No change in cell volume

3. A piece of plant tissue is transferred from a beaker of water into a 10% sucrose solution. What happens to the tissue?

Movement of water Volume of tissue cells

A Enters the cells Decreases

B Enters the cells Increases

C Leaves the cells Decreases

D Leaves the cells Increases

4. 4 strips are cut from a fresh potato. The length of each strip is measured. One strip is placed in water, and the others in different concentrations of sugar solution. After an hour, the strips are measured again. The results are shown in the table. Which liquid is water?

Initial length (mm) Final length (mm)

A 83 83

B 79 82

C 80 78

D 82 81

5. The figure shows the condition after a plant cell is put in a high concentrated salt solution for 10 minutes. Which of the following structures is semi-permeable?

A. P onlyB. Q and RC. Q and SD. Q, R and S

6. An experiment is conducted to study osmosis in red blood cells. What would happen if a drop of blood is put in distilled water? The red blood cells will

A. Crenate

B. Coagulate

C. Haemolyse

D. Remain normal

7. The above conditions occur when a plant cell is immersed in ______

A. Hypotonic solution

B. Isotonic solution

C. Hypertonic solution

D. Distilled water

• Flaccid

•Vacuole become small •Cytoplasm shrinks

•Plasma membrane separates from the cell wall

8. The bursting of red blood cell is known as _______ and it happen when the RBC is put in ______.

Condition of RBC Solution

A Haemolysis Hypertonic

B Crenation Hypertonic

C Haemolysis Hypotonic

D Plasmolysis Hypotonic

9. Excessive use of fertilizers on plant will lead to the wilting of the plant. Which of the following are correct sequences of the wilting phenomena?

A. Water moves out ---plasmolysis --- turgid --- wilting

B. Water moves into ---plasmolysis --- flaccid --- wilting

C. Water moves into ---plasmolysis --- turgid --- wilting

D. Water moves out ---plasmolysis --- flaccid --- wilting

A solution in which the concentration of solute outside the cell is lower than the concentration of solute inside the cell

10. Explanation above refer to the _____.

A. Isotonic solution

B. Hypertonic solution

C. Hypotonic solution

D. Distilled water

conclusion

Hypotonic Hypotonic Hypertonic

Types of solution

Effect on cells

plant plant plant

animal animal animal

lysis normal crenation

turgid plasmolysisnormal