Osmosis, Diffusion, and Cell Transport

Biology II

Standards1. Matter tends to be cycled within an ecosystem, while energy is transformed and eventually exits an ecosystem

2. The size and persistence of populations depend on their interactions with each other and on the abiotic factors in an ecosystem

3. Cellular metabolic activities are carried out by biomolecules produced by organisms

4. The energy for life primarily derives from the interrelated processes of photosynthesis and cellular respiration. Photosynthesis transforms the sun’s light energy into the chemical energy of molecular bonds. Cellular respiration allows cells to utilize chemical energy when these bonds are broken.

5. Cells use the passive and active transport of substances across membranes to maintain relatively stable intracellular environments

6. Cells, tissues, organs, and organ systems maintain relatively stable internal environments, even in the face of changing external environments

7. Physical and behavioral characteristics of an organism are influenced to varying degrees by heritable genes, many of which encode instructions for the production of proteins

8. Multicellularity makes possible a division of labor at the cellular level through the expression of select genes, but not the entire genome

9. Evolution occurs as the heritable characteristics of populations change across generations and can lead populations to become better adapted to their environment

Warm-up (9-9-14)

Is it important to learn proper techniques for handling technology within the lab?

What are some capabilities technology has given people throughout the last decade? (Think of some capabilities that are science related too!!)

Outline for the day

• Objectives• LabQuest Demo & exploration

Objectives

• To explore the LabQuests and learn how to properly use Logger Pro and the new lab technology

Warm-up (9-10-14)

• Cross off the box for today’s warm-up. We will not be using it.

• Please make sure that 4 of you are logged on to the laptops next door.

• After you are logged on, come back in this room and be prepared for more instructions.

Warm-up (9-11-14)

• Explain some of the capabilities of Logger Pro that you learned yesterday that you maybe didn’t know before.

Warm-up (9-12-14)

• While working with Logger Pro, do you ever need to open up a Word document to type?

• What is one of the easiest and quickest ways to get information if you and your group members don’t know how to do something?

Outline for the day

• Objectives• Work Time

Objectives

• To explore LabQuest and Logger Pro and to teach the class how to perform various functions that they may not have known before

Warm-up (9-15-14)

• When using the LabQuests, what are the procedures for turning it on?

• When using the LabQuests, what are the procedures for turning it off?

• How do you switch between pages in Logger Pro?

Outline for the day

• Objectives• Work Time

Objectives

• To explore LabQuest and Logger Pro and to teach the class how to perform various functions that they may not have known before

• To present our Logger Pro assignments and learn new functions of Logger Pro.

Warm-up (9-16-14)

• When using Logger Pro, what is the procedure for making Logger Pro save each run automatically?

• If I don’t set the preferences to save automatically, what must I do?

Outline

• Objectives• Present Logger Pro• Any final questions• Transport Notes

Objectives

• To present our Logger Pro assignments and learn new functions of Logger Pro.

Warm-up (9-17-14)

• What does cell transport mean? What does it make you think about?

• How is cell transport involved in the transmission of the Ebola virus?

Outline for the day

• Objectives• Anatomy of an egg• Why do I care?

Objectives

• To introduce the concepts of cell transport and the different types of transport

• To explain the processes of diffusion and osmosis

• Determine the types of transport and how a cell maintains a stable internal environment.

Anatomy of an Egg

• https://www.exploratorium.edu/cooking/eggs/eggcomposition.html

Why do I care?

• You are made of cells… Without cell transport you would not be alive!

• The movement of various solutes can contribute to a variety of bodily functions that occur in your daily lives.– Sodium / Potassium pump

Lab Notebook Setup

• Number your notebook starting with page 1 in the very front. Number both front and back of the pages.

• Composition notebook, the first 2 pages front and back (pages 1-4) will be used for the table of contents

• Make sure to label each of these pages.

p. 5 Egg Anatomy

• Predict: (What do you think is going to happen? What do you notice before?)

• Observe: (What do you notice? What is happening? What is the end result?)

• Explain: (Why did this happen? What does this show? Why is this important?)

p. 6 Strainer Transport

• Predict:

• Observe:

• Explain:

Strainer Transport

• What does the strainer represent?

• What could the substances going through the strainer represent?

• Can the material only go one way?

• What do you know about the concentrations of the substances on either side of the membrane?

Types of Transport

• Three types of transport in cells1. Passive Transport: does not use the cell’s energy in bringing materials in & out of the cell2. Active Transport: does use the cell’s energy in bringing materials in & out of the cell3. Bulk Transport: involves the cell making membrane bound vesicles to bring materials in & out of the cell

Passive Transport

• There are 3 types of passive transport:1. Diffusion: involves small or uncharged molecules entering & leaving the cell2. Osmosis: involves water entering & leaving the cell3. Facilitated Diffusion: involves large or charged molecules that need a protein helper to get in & out of the cell

Diffusion

• Diffusion is the net movement of a substance (liquid or gas) from an area of higher concentration to one of lower concentration. A drop of dye in water is concentrated but then begins to disperse through out the water moving from an area of high to an area of low concentration.

Warm-up (9-18-14)

• Why is it necessary to have a separate definition for the diffusion of water?

• What is the difference between active and passive transport?

Outline for the day

• Objectives• Check Egg Experiment• Cell Transport Notes

Objectives

• To explain the processes of diffusion and osmosis

• Determine the types of transport and how a cell maintains a stable internal environment.

Diffusion• When the substance has fully

dispersed through out the container, it has reached equilibrium.

• What do you notice about the picture?

• When equilibrium has been reached, there is no longer a concentration gradient.

• A concentration gradient is the difference in concentration between two areas.

Diffusion

• Certain molecules can freely diffuse across the cell membrane.

• Look at the picture - hydrophobic molecules and small uncharged molecules can diffuse through the membrane but large molecules or ions (atoms with a positive or negative charge) can not move through the membrane.

Osmosis

• Osmosis is the diffusion of water from an area of high concentration to an area of low concentration across a membrane.

• Cell membranes are completely permeable to water and the amount of water in the environment has a large effect on the survival of a cell.

The picture shows a tube separated by a membrane and how the water moves from an area of high concentration to an area of low.

Osmosis

• There are 3 types of solutions that involve water and how they affect the cell.

1. Hypertonic Solution: the solution the cell is placed in has less water than the cell 2. Hypotonic Solution: the solution the cell is placed in has more water then the cell 3. Isotonic Solution: the solution the cell is placed in has equal amount of water as the cell

Hypertonic Solution

• Hypertonic solution: higher concentration of water inside the cell than outside the cell. – more solute (salt, sugar, etc.) than the cell• causes there to be less water in the solution.

– Water flows from an area of high concentration to an area of low and leaves the cell. • causes the cell to shrivel.

Shriveling Cells

• Water Loss =• In animal cells, the shriveling is called

crenating. • In plant cells, plasmolysis occurs and the cell

membrane shrinks away from the cell wall.• Death will result in both cells.

Hypotonic Solution

• Hypotonic solution: higher percentage of water than the cell. – less solute than the cell and causes the solution to

have more water than the cell. – When a cell is placed in a hypotonic solution,

water flows from an area of high concentration to an area of low and rushes into the cell. • causes the cell to expand and possibly burst.

Cell Swelling

• In animal cells, the cell bursts or will lyse, killing the cell.

• In plant cells, the cell membrane is pressed up against the cell wall but the cell wall does not allow the cell to expand anymore and the plant cell does not die.

Warm-up (9-22-14)

• Divide your box in half. On one half label it isotonic, on the other half, label it hypertonic.

• Draw a picture of an isotonic solution.

• Draw a picture of a hypertonic solution.

Outline for the day

• Objectives• Egg observations• Cell Transport with an Egg• Simulation Review of hypertonic, isotonic, and

hypotonic

Objectives

• To review hypertonic, hypotonic, and isotonic solutions.

Eggsperiment!

• Record your observations of the egg in your composition notebooks.

• Feel free to touch the egg. Be careful!

Review!

Hypertonic, Hypotonic, Isotonic

• http://www.phschool.com/science/biology_place/biocoach/biomembrane1/solutions.html

• Egg Osmosis• https://

www.youtube.com/watch?v=SSS3EtKAzYc• Osmosis and water potential (9-23)• http://

www.youtube.com/watch?v=nDZud2g1RVY

Cell Transport Review

• https://www.youtube.com/watch?v=kfy92hdaAH0

Warm-up (9-23-14)

• Explain what you learned from the egg demonstration.

Outline for the day

• Objectives• Notes Scavenger Hunt

Objectives

• To discover more information about cell transport and the structure of membranes

Review!

Hypertonic, Hypotonic, Isotonic

• http://www.phschool.com/science/biology_place/biocoach/biomembrane1/solutions.html

• Egg Osmosis• https://

www.youtube.com/watch?v=SSS3EtKAzYc• Osmosis and water potential (9-23)• http://

www.youtube.com/watch?v=nDZud2g1RVY

Osmosis

• Why is there a separate definition for the diffusion of water??– Living systems have semipermeable membranes– This may or may not allow the passage of a solute

• Remember that water is a solvent!

– LAWS OF DIFFUSION WON’T WORK• Solute concentration (diffusion) has to be replaced by water

potential.• Living systems create the need for the concept of osmosis

– What is water potential?• The sum of the effect of pressure and solute potentials

Water Potential

• ᴪ (Psi) = ᴪs + ᴪ p

• Made of pressure potential and solute potential– Pressure potential: how much water the cell

already has– Solute potential: how much solute is dissolved• This influences pressure potential

– Water flows from areas of high water potential to low water potential

Isotonic Solution

• isotonic solution: same percentage of water on the outside of the cell as the inside of the cell.– same amount of solute as the inside of the cell. – Water moves at a constant rate in and out of the

cell and the cell maintains its original shape.

Isotonic Solution

• In animal and plant cells, the cell keeps its shape when in an isotonic solution. Most cells live in an isotonic environment and they are able to maintain their shape and survive.

Hypertonic and Hypotonic Solutions

• The plant cell to the left is placed in distilled water and salt solution. Notice what happens to the cell in the different types of solutions.

Hypertonic and Hypotonic Solutions

• The red blood cell to the right is placed in distilled water and salt solution. Notice what happens to the cell in the different types of solutions.

Facilitated Diffusion

• Some molecules are too large to pass through the cell membrane by diffusion and need help to cross. These molecules use facilitated diffusion.

• Facilitated diffusion is the flow of large molecules from an area of high concentration to an area of low using proteins in the cell membrane.

Facilitated Diffusion

• Glucose is able to enter our cells from the blood stream by facilitated diffusion. A glucose molecule is too big to squeeze through the phospholipid bilayer and needs protein channels to help it pass into the cell. These protein “helpers” are extremely important because they allow much needed molecules to enter our cells. With out them, our cells would not have glucose and our cells would not be able to make energy.

Active Transport

• The types of transport discussed so far are passive transport and do NOT require a cell to use its energy- the molecules flow with the concentration gradient. There are times when the cell wants to pump against the gradient and to do so, it must use energy. The use of energy to pump molecules against the gradient is called active transport. A cell uses energy in the form of ATP (adenosine tri- phosphate). When energy is taken from ATP, it turns into ADP.

Bulk Transport

• The last kind of cell transport is bulk transport. • Bulk transport involves the cell membrane making

vesicles to bring materials in and out of the cell. There are two kinds of bulk transport:

1. Exocytosis: moving materials OUT of the cell.2. Endocytosis: moving materials INTO the cell. There are 2 types of endocytosis:

1. Pinocytosis: bringing small molecules or liquids into the cell2. Phagocytosis: bringing large molecules into the cell

Exocytosis

• Exocytosis is the process of exporting materials out of the cell by forming a membrane bound vesicle around the materials. The cell uses exocytosis to get rid of cell waste or to export proteins made in the cell to give to other cells.

• The proteins or waste are taken to the golgi body where the materials are packaged into a membrane bound vesicle. The vesicle then merges with the cell membrane and the materials are released into the outside environment.

Endocytosis and Pinocytosis

• Endocytosis is the movement of materials into the cell through membrane bound vesicles. One type of endocytosis is called pinocytosis, or “cell drinking”.

• Pinocytosis is the movement of small molecules or liquids into the cell through bulk transport.

• The small molecules make contact with the cell membrane and the cell membrane pinches off around the molecules. Pinocytosis is how animal cells make vacuoles (water filled sacs).

Endocytosis - Phagocytosis

• The other type of endocytosis is phagocytosis, or “cell eating”. Phagocytosis is the movement of large molecules into the cell through bulk transport.

• The large molecules make contact with the cell membrane and the cell membrane pinches off around the molecules. The lysosomes then fuse with the vesicle and break down the large molecules into nutrients. Phagocytosis is how white blood cells engulf bacteria and break them down.

Endocytosis

Warm-up (9-24-14)

• Explain what crenation is and why this would happen to a cell. (you may need to look back in your notes to find the answer)

Outline for the day

• Objectives• Cell Membrane Model

Objectives

• Build a model of a cell membrane and explain the components

Cell Membranes

• Permeability…– What does this mean?– What is allowed to cross the barrier• Impermeable• Permeable• Semipermeable

Why talk about cell transport when we don’t even know what the items are

transported through?!

Cell Membrane• Now that we know the function, let’s look at

the structure to get a better understanding.• http://

www.youtube.com/watch?v=S7CJ7xZOjm0• More Cell Membrane Notes and Information• http://alevelnotes.com/Cell-Membranes/12

Build a Membrane

• You will have time to work to build your own model membrane.

• I would like these to look really good so I can use them in the future.

• Take your time, put in the effort and the work to produce a good final product.

• Yes, you may color them!

Warm-up (9-25-14)

• What is Exocytosis and how is this important to the cell?

• What is Endocytosis and how is this important to the cell?

Outline for the day

• Objectives• Cell Membrane Model

Objectives

• Build a model of a cell membrane and explain the components

Build a Membrane

• You will have time to work to build your own model membrane.

• I would like these to look really good so I can use them in the future.

• Take your time, put in the effort and the work to produce a good final product.

• Yes, you may color them!

Warm-up (9-26-14)

• What is facilitated diffusion and why is it important?

Outline for the day

• Objectives• Cell Membrane Model

Objectives

• Build a model of a cell membrane and explain the components

Why talk about cell transport when we don’t even know what the items are

transported through?!

Cell Membrane• Now that we know the function, let’s look at

the structure to get a better understanding.• http://

www.youtube.com/watch?v=S7CJ7xZOjm0• More Cell Membrane Notes and Information• http://alevelnotes.com/Cell-Membranes/12

• Osmosis and water potential (9-23)• http://www.youtube.com/watch?v=nDZud2g1

RVY

Quiz!!

• http://wps.prenhall.com/esm_krogh_biology_3/17/4436/1135738.cw/

• Test your progress on understanding active and passive transport.

• Report your score to me!

Warm-up (9-29-14)

• What is diffusion?

• What is osmosis? Why is it necessary and what makes it different from diffusion?

Outline for the day

• Objectives• Lab Prep

Objectives

• To prepare for the lab that will demonstrate osmosis

Lab Prep

• Lab 1A and Lab 1B

Warm-up (9-30-14)

• What is the purpose of the lab 1A?

Outline for the day

• Objectives• Lab 1A

Objectives

• To explore the concept of osmosis and diffusion using dialysis tubing

Warm-up (10-1-14)

• Write down your hypothesis for the lab 1A• Go make sure that your lab stations are set up

and the computers and labquests are turned on and ready to go!

Outline for the day

• Objectives• Lab 1A

Objectives

• To explore the concept of osmosis and diffusion using dialysis tubing

Warm-up (10-2-14)

• Explain what you learned from the start of the experiment yesterday

• Go make sure that your lab stations are set up and the computers and labquests are turned on and ready to go!

Outline for the day

• Objectives• Lab 1A wrap up• Lab 1B prep

Objectives

• To explore the concept of osmosis and diffusion using dialysis tubing

• To prepare for the second portion of the lab

Warm-up (10-3-14)

• Explain how these labs are helpful to understanding cell transport.

Outline for the day

• Objectives• Lab 1B

Objectives

• To explore the concept of cell transport and to demonstrate how this works by completing the lab.

Warm-up (10-6-14)

• What would you have expected the pressure to do in the osmosis lab? (even though we may not have seen it)

Outline for the day

• Objectives• Lab 1B

Objectives

• To explore the concept of cell transport and to demonstrate how this works by completing the lab.

Warm-up (10-7-14)

• In the osmosis lab, what is one reason that the results showed up as they did?

Outline for the day

• Objectives• Lab 1B

Objectives

• To explore the concept of cell transport and to demonstrate how this works by completing the lab.

Warm-up (10-8-14)

• How could the osmosis lab have been performed in order to get more accurate results?

• In other words, what should we have done differently in the lab?

Outline for the day

• Objectives• Lab 1 Review / Follow up

Objectives

• To explore the concept of cell transport and to demonstrate how this works by completing the lab.

Warm-up (10-9-14)

• Write down everything you can remember about cell transport and the labs we did in this unit.

Outline for the day

• Objectives• Test

Objectives

• To demonstrate knowledge of cell transport by taking the test.

Warm-up (10-10-14)

• What is special about carbon compounds?

• What are the four main carbon compounds?

Outline for the day

• Objectives• Carbon Compound Review

Objectives

• To review previous knowledge of carbon compounds and their purposes.

4 Main Carbon Compounds

• Proteins• Carbohydrates• Lipids• Nucleic Acids

Carbohydrates

• What are they?– Molecules composed of carbon, hydrogen, and oxygen– Sugars and starches– Can be broken down to provide a source of usable

chemical energy for cells– Major part of plant cell structure– Monosaccharides – most basic

• Glucose

– Disaccharides– Polysaccharides

• Polymers of monosaccharides

Cellulose vs. Starches and Glycogen

• Cellulose has different bonding of glucose monomers

• Starches are made and stored by plants, and can be broken down as source of energy by plant and animal cells

• Glycogen – made and stored by animals is more highly branched than plant starches

Lipids

• Nonpolar molecules• Fats, oils, cholesterol• Contain chains of carbon atoms bonded to oxygen and

hydrogen atoms• Some can be broken down for energy• Some are part of cell structure• Fats and oils both contain glycerol bonded to fatty

acids– Chains of carbon atoms bonded to hydrogen atoms

• 3 fatty acids bonded to glycerol – triglycerides

Lipids

• Saturated– Most animal fats– Every place that a hydrogen atom can bond to a

carbon atom is filled with a hydrogen atom. – All single bonds

• Unsaturated– Oils– Fewer hydrogen atoms because there is at least one

double bond between carbon atoms– Double bonds make kinks

Think about it

• Why would the kinks in the unsaturated fats be important in living organisms?

• Think about how those molecules fit together.

Proteins

• Most varied of carbon-based molecules in organisms

• Polymer made of monomers (amino acids)– Molecules contain carbon, hydrogen, oxygen,

nitrogen, and sometimes sulfur– 20 different amino acids– Our bodies can make 12– Others come from foods• Meat, beans, nuts

Amino Acids in Proteins

• Form peptide bonds– Covalent bonds formed between the amino group of one

amino acid and the carboxyl group of another amino acid.– Through peptide bonds, amino acids are linked into

chains called polypeptides• A protein is one or more polypeptides• Specific sequence of amino acids determines a

protein’s structure and function– Alpha helix– Beta pleated sheet

Nucleic Acids

• Provide detailed instructions to build proteins• Long carbon-based molecules• Polymers made up of nucleotides– Nucleotide is composed of sugar, phosphate group, and

nitrogen-containing molecule (base)• Only have one function – work together to make proteins• Two Types

1. DNA = stores the info for putting amino acids together to make proteins

2. RNA = helps to build proteins