Diffusion & OsmosisDiffusion & Osmosis

Schema ActivatorSchema Activator Evaluate the following claims:Evaluate the following claims:

– 9 out of 10 people surveyed say that the bag 9 out of 10 people surveyed say that the bag lunches at GPA are among the best they’ve lunches at GPA are among the best they’ve ever hadever had

– 100% of people surveyed say that cell phones 100% of people surveyed say that cell phones and music players should not be allowed in and music players should not be allowed in schoolsschools

– What questions come to mind when you read What questions come to mind when you read these statements?these statements?

Movement of MaterialsMovement of Materials

We have looked at cells and the We have looked at cells and the structures that help make and structures that help make and transport materials throughout the transport materials throughout the cellcell

How do the materials enter and leave How do the materials enter and leave the cell?the cell?

Cell membrane- Cell membrane- selectively selectively permeable…permeable…write what you think this write what you think this means in your science notebooksmeans in your science notebooks

Define selectively permeable Define selectively permeable membranemembrane

A membrane that allows only certain A membrane that allows only certain materials to cross it materials to cross it

Materials pass through Materials pass through porespores in the in the membranemembrane

Structure of Cell MembraneStructure of Cell Membrane

Lipid bilayerLipid bilayer Hydrophilic headsHydrophilic heads Hydrophobic tailsHydrophobic tails Carrier proteinsCarrier proteins

The cell membrane has a unique The cell membrane has a unique structure that controls how things enter structure that controls how things enter and leave the cell, referred to as the and leave the cell, referred to as the fluid fluid mosaic modelmosaic model

How Materials MoveHow Materials Move

Materials move through the cell Materials move through the cell membrane through a process called membrane through a process called DiffusionDiffusion

Write down what you think diffusion Write down what you think diffusion is in your science notebook.is in your science notebook.

http://www.brainpop.com/science/http://www.brainpop.com/science/matterandchemistry/diffusion/matterandchemistry/diffusion/

Define DiffusionDefine Diffusion

The movement of molecules from a The movement of molecules from a area in which they are highly area in which they are highly concentrated to a area in which they concentrated to a area in which they are less concentrated. are less concentrated.

Draw a diagram of an example of Draw a diagram of an example of diffusion we saw in class.diffusion we saw in class.

See an animation of See an animation of diffusion here:diffusion here:

http://http://lewis.eeb.uconn.edu/lewis.eeb.uconn.edu/lewishome/applets/lewishome/applets/

Diffusion/diffusion.html Diffusion/diffusion.html

Define osmosisDefine osmosis

Define osmosisDefine osmosis

The diffusion of The diffusion of waterwater across a across a selectively permeable selectively permeable membranemembrane. .

Define osmosisDefine osmosis    Water moves from a high Water moves from a high

concentration of water (less salt or concentration of water (less salt or sugar dissolved in it) to a low sugar dissolved in it) to a low concentration of water (more salt or concentration of water (more salt or sugar dissolved in it).  This means sugar dissolved in it).  This means that water would cross a selectively that water would cross a selectively permeable membrane from a dilute permeable membrane from a dilute solution (less dissolved in it) to a solution (less dissolved in it) to a concentrated solution (more concentrated solution (more dissolved in it).dissolved in it).

http://www.usd.edu/~bgoodman/Osmos.htm

http://www.usd.edu/~bgoodman/Osmos.htm

Define osmosisDefine osmosis

Define osmosisDefine osmosis In this picture a red blood In this picture a red blood

cell is put in a glass of cell is put in a glass of distilled water (all water distilled water (all water with no salt or sugar in it).  with no salt or sugar in it).  Because there is a higher Because there is a higher concentration of water concentration of water outside the cell, water outside the cell, water enters the cell by enters the cell by OSMOSISOSMOSIS.  In this case too .  In this case too much water enters and the much water enters and the cell swells to the point of cell swells to the point of bursting open.  In the end bursting open.  In the end pieces of cell membrane pieces of cell membrane are left in the water. are left in the water.

http://www.usd.edu/~bgoodman/Osmos.htm

See an animation of See an animation of osmosis here:osmosis here:

http://lewis.eeb.uconn.eduhttp://lewis.eeb.uconn.edu/lewishome/applets/Osmos/lewishome/applets/Osmosis/osmosis.htmlis/osmosis.html

For more information on For more information on diffusion & osmosis, click diffusion & osmosis, click

here:here:

http://edtech.clas.pdx.edu/osmosis_thttp://edtech.clas.pdx.edu/osmosis_tutorial/default.htmlutorial/default.html

Types of Passive TransportTypes of Passive Transport

DiffusionDiffusion OsmosisOsmosis Facilitated DiffusionFacilitated Diffusion

– Carrier ProteinsCarrier Proteins– Ion channelsIon channels

Some always openSome always openSome gatedSome gated

http://www.brainpop.com/science/http://www.brainpop.com/science/cellularlifeandgenetics/passivetransport/cellularlifeandgenetics/passivetransport/

Why are osmosis & diffusion Why are osmosis & diffusion important?important?

All living things have certain requirements All living things have certain requirements they must satisfy in order to remain alive – they must satisfy in order to remain alive – maintain maintain homeostasishomeostasis

These include exchanging gases (usually These include exchanging gases (usually CO2 and O2), taking in water, minerals, CO2 and O2), taking in water, minerals, and food, and eliminating wastes. and food, and eliminating wastes.

These tasks happen at the cellular level.These tasks happen at the cellular level. Molecules move through the cell Molecules move through the cell

membrane by diffusionmembrane by diffusion

Active TransportActive Transport If passive transport is the movement of materials If passive transport is the movement of materials

from an area of greater to lesser concentration, from an area of greater to lesser concentration, what do you suppose what do you suppose active active transporttransport is? Write is? Write your answer in your science notebookyour answer in your science notebook

Types of Active Transport:Types of Active Transport: Cell Membrane PumpsCell Membrane Pumps EndocytosisEndocytosis ExocytosisExocytosis

http://www.brainpop.com/science/http://www.brainpop.com/science/cellularlifeandgenetics/activetransport/cellularlifeandgenetics/activetransport/

Endocytosis & ExocytosisEndocytosis & Exocytosis

Review Osmosis & Review Osmosis & Diffusion Here:Diffusion Here:

http://wappingersschools.org/WJhttp://wappingersschools.org/WJH/teachers/science/Jim_Site/asigH/teachers/science/Jim_Site/asig

nments/cells/diffusionetc/nments/cells/diffusionetc/diffusion_osmosis.html diffusion_osmosis.html

HomeworkHomework

Read pp. 95-100Read pp. 95-100 Do questions 1-6 on pg. 100Do questions 1-6 on pg. 100

Read pp. 100-104Read pp. 100-104 Do questions 1-6 on pg. 104Do questions 1-6 on pg. 104