Transport across the membrane
This presentation is the property of its rightful owner.
Sponsored Links
1 / 30

Transport Across The Membrane PowerPoint PPT Presentation


  • 156 Views
  • Uploaded on
  • Presentation posted in: General

Transport Across The Membrane. Osmosis. Objectives of unit:. Explain passive transport mechanisms of diffusion and facilitated diffusion, including the role of channel and carrier proteins Define the process of osmosis Explain the process of active transport and the role of proteins and ATP

Download Presentation

Transport Across The Membrane

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Transport across the membrane

Transport Across The Membrane

Osmosis


Objectives of unit

Objectives of unit:

  • Explain passive transport mechanisms of diffusion and facilitated diffusion, including the role of channel and carrier proteins

  • Define the process of osmosis

  • Explain the process of active transport and the role of proteins and ATP

  • Explain the processes of endocytosis and exocytosis

  • Describe the properties of gas exchange surfaces in living organisms

  • Explain how the structure of the mammalian lung is adapted for rapid gaseous exchange


What can you remember about osmosis fro igcse gcse convert pointer to pen tool by right clicking

What can you remember about osmosis fro IGCSE/GCSE? (convert pointer to pen tool by right clicking)

Osmosis


The diffusion of solvent molecules such as water is known as osmosis

The diffusion of solvent molecules, such as water, is known as osmosis

water

Solvent molecules

e.g. water

glucose

Solute molecules

e.g.glucose

Water is the solvent used in nature


The definition of osmosis is

The definition of osmosis is:

Osmosisis the net movement of solvent molecules from a region of their high concentration to one of their low concentration across a partially permeable membrane


Question 1 complete the definition

Question 1: Complete the definition

Osmosisis the net movement of solvent

molecules from a region of their high

concentration to one of their low concentration

across a partially permeable membrane

answer


Osmotic concentration relates to the amount of dissolved solutes in a solution

Osmotic concentration relates to the amount of dissolved solutes in a solution

high osmotic concentration

low osmotic concentration

(concentrated)

(dilute)

Insoluble molecules do not affect the osmotic concentration


Water molecules will move down their concentration gradient

Water molecules will move down their concentration gradient


Partially permeable membranes only let water and very small molecules through

Partially permeable membranes only let water and very small molecules through

A partially permeable membrane results in an uneven distribution across the membrane

Low osmotic concentration:

A dilute solution with a high water potential

High osmotic concentration:

A concentrated solution with a low water potential


Which way will osmosis occur

Which way will osmosis occur?

NET osmosis

water

glucose

high osmotic concentration

low osmotic concentration

partially permeable membrane


Osmosis can be modelled using an osmometer

Osmosis can be modelled using an osmometer

Water molecules enter the tubing by osmosis

Water molecules leaves the tubing by osmosis

30 minutes later

30 minutes later

Sucrose

solution

Pure water

Sucrose

solution

Pure water


Question 2 an osmometer was used to investigate the affect of temperature on osmosis

Question 2: An osmometer was used to investigate the affect of temperature on osmosis:

  • Calculate the averages and plot a graph to illustrate the affect of temperature on the rate of osmosis.

  • Explain the results.

answer


Isotonic solutions have the same osmotic concentration as the cytoplasm of the cell

Isotonic solutions have the same osmotic concentration as the cytoplasm of the cell

external solution

blood cell

No NET osmosis

Cell just not change


Hypertonic solutions have a higher osmotic concentration than the cytoplasm of the cell

Hypertonic solutions have a higher osmotic concentration than the cytoplasm of the cell

external solution

blood cell

NET osmosis out of the cell

Causes animal cells to shrink


Hypotonic solutions have a lower osmotic concentration than the cytoplasm of the cell

Hypotonic solutions have a lower osmotic concentration than the cytoplasm of the cell

external solution

blood cell

NET osmosis into the cell

Can cause animal cells to burst


Question 3 match the terms with the definitions

Question 3: Match the terms with the definitions

isotonic

lower concentration than cell cytoplasm

hypotonic

higher concentration than cell cytoplasm

hypertonic

Same concentration as cell cytoplasm

answer


Question 4

Question 4:

A scientist placed some red blood cells in a solution and viewed the cells with a light microscope. After a few minutes she noticed that many of the cells burst.

Explain why this may have occurred.

answer


Osmosis in red onion cells

Osmosis in red onion cells

Hypertonic solution

Hypotonic solution

Isotonic solution

osmosis

osmosis

osmosis

Incipient plasmolysis

Full plasmolysis

Turgor

Causes a plant to wilt

Cell wall exerts an inward pressure


Question 5 match the label to the solution

Question 5: Match the label to the solution

B

A

C

1. Isotonic solution 2. hypertonic solution 3. hypotonic solution

answer


Question 6 predict with reasons what will happen to the flowers in the diagram below

Question 6: Predict, with reasons, what will happen to the flowers in the diagram below:

very salty water

answer


Summary

Summary:

  • Keywords you need to know the meaning of:

  • Osmosis

  • Partially permeable membrane

  • Isotonic

  • Hypertonic

  • Hypotonic

  • Turgor

  • Plasmolysis


Activity

Activity

  • Read pages 106 – 107

  • Make brief notes

  • Answer questions 1 and 2 on page 107


Transport across the membrane 1196057

End

www.clickbiology.com

Answers to questions


Question 1 answer

Question 1 answer

Osmosisis the net movement of solvent

molecules from a region of their high

concentration to one of their low concentration

across a partially permeable membrane


Question 2 answer

Question 2 answer

20

18

16

14

12

10

8

6

4

2

x

x

x

Rate of osmosis

mm/min

x

x

x

10 20 30 40 50

Temperature/oC

With increasing temperature the water molecules gain kinetic energy;

Increasing the rate of osmosis


Question 3 answer

Question 3 answer

isotonic

lower concentration than cell cytoplasm

hypotonic

higher concentration than cell cytoplasm

hypertonic

same concentration as cell cytoplasm


Question 4 answer

Question 4 answer

The solution was hypertonic;

So water entered the cells;

By osmosis;

Causing them to swell and burst


Question 5 answer

Question 5 answer

2

B

3

A

1

C

1. Isotonic solution 2. hypertonic solution 3. hypotonic solution


Question 6 answer

Question 6 answer

The salty water is hypertonic;

As it has a higher osmotic concentration than the cell cytoplasm;

So water leaves the cells of the stems;

By osmosis;

Causing the cells to plasmolyse;

And the flowers to wilt;


Transport across the membrane 1196057

END

www.clickbiology.com


  • Login