Homework:

Homework:Read pages 182-189 (Section 7-3): Take notes based on the questions on the back of Assignment Sheet and write your answers in your notebook.

Do Now: (in your notebook) Which molecule is bigger, starch or glucose?

Explain with a diagram in our notebook. Today’s Objectives:

Design an experiment by drawing from your knowledge of starch, glucose, cell membranes, and experimental indicators that test for the presence of starch and glucose.

Bio 9C: Thursday, 12.2.10Title: Movement Across Cell Membranes – Day 1

MOVEMENT ACROSS CELL MEMBRANESMoretti and Dickson

Planning the Experiment: Individual:

Read Overview Small Groups:

Planning the Experiment How do we test for Starch

and Glucose? Whole Class Discussion

Designing a Lab:Diffusion Across Cell Membranes

Objectives for Class: Design an experiment by drawing from your knowledge of starch,

glucose, cell membranes, and experimental indicators that test for the presence of starch and glucose.

Water

Model Cell w/ Dialysis Tubing Membrane

Starch & Glucose Solution

Class Discussion: Starch

How do we test for it? Use Iodine

How do we know starch has passed through membrane? Iodine outside the dialysis bag turns from yellow-orange to purplish-

brown Glucose

How do we test for it? Boil it in Benedicts solution or use a glucose test strip

How do we know glucose has passed through the membrane? Glucose test strip will change color




Planning the Experiment: Individual:

Read Overview Small Groups:

Planning the Experiment How do we test for Starch and

Glucose? Whole Class Discussion Small Group:

Experimental Set-Up Whole Class Review:

Experimental Set-Up




Water

Model Cell w/ Dialysis Tubing Membrane


Demo What is happening to the dye in the water? Based on prior knowledge, what do you think

this is called?

Concentration How much “stuff” is in a given amount of liquid Mass of a solute (stuff in the liquid) per a given

volume of the total solution i.e.: 12g of salt in 3L of water = 12g/3L = 4g/L

Diffusion Movement of molecules from a

high concentration (more stuff) to low concentration (less stuff)

Osmosis Movement of water through a selectively

permeable membrane from a high concentration to low concentrationNote: For osmosis to occur, the membrane only allows water to pass across and not the solute

New Vocabulary

Objectives for Class: Use scientific vocabulary to explain how a cell membrane controls what

enters and leaves a cell

Diffusion

Osmosis

Selective Permeability When a cell membrane (or

any membrane for that matter) only allows certain materials to pass across the membrane and not others

Substance usually pass across based on the size, shape, and charge (+/-/neutral) of the molecules

New Vocabulary



Diffusion, Osmosis and Selective Permeability In Action:

http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm

New Vocabulary





Homework:Type the following sections of the Diffusion Lab:

Background Info Purpose/Hypothesis Summary of Procedure

Do Now: (in your notebook) Take out lab prep and get ready to review

procedures Today’s Objectives:

Design an experiment to test diffusion of starch and glucose across a membrane

Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

Bio 9C: Friday, 12.3.10Title: Movement Across Cell Membranes – Day 2

Review Experimental Set-Up: Part I:

Set-up Dialysis Bag Moisten tube and tie one end Add the starch & glucose solution to the tube Tie the top of the tube

Rinse w/ tap water to wash excess solution from outside of bag

Set-up Beaker Fill a 250 ml beaker ¾ of the way with water Add Iodine to water – mixture should be orange-ish

Put dialysis bag into beaker with water and iodine Part II: Wait 30 min to allow for substances to

move across the membrane


Water and Iodine




Review Experimental Set-Up: Part III:

How do you know the following substances have left the bag: Starch? Glucose?

What other substances might move across the bag? How will you know?




Water and Iodine


Review Experimental Set-Up: Part I:

Preparing Dialysis Bag Soak the dialysis tube in water to soften Tie one end into a knot Fill the tube about half-way w/ starch/ glucose solution Tie the other end of the tube into a knot to seal the bag Rinse w/ tap water to wash excess solution from outside of bag

Preparing the Beaker Label your beaker Fill a 140 ml beaker ¾ of the way with water Add 10-15 drops of Iodine to water and mix . Note the color of the water Test water with glucose test strip and note any color change

Preparing the Model: Put dialysis bag into beaker with water and iodine solution

Part II: Wait 30 min to allow for substances to move across the membrane

Part III: Data Collection

Diagram the experimental set-up Create a data table to collect data Collect data by recording any color change to

the beaker, dialysis bag, and/or glucose test strip.

Implementing the Lab:Diffusion Across Cell Membranes

Water and Iodine


Lipid Bilayer Two layers of lipids that form

the outer membrane of a cell. Flexible Strong Do not Dissolve in water

New Vocabulary



Image to the right shows the lipid bilayer of a cell. Notice how it has other components like protein channels & “pumps” built into it.

zoom out

Homework:Finish Typing the Following Section of the Lab:

Data/ Results Analysis Conclusion

Bring in a printed copy of your background information section to class on Monday!!!

Do Now: What is the purpose of the lab?

Today’s Objectives: Use scientific vocabulary to explain how a cell membrane controls what

enters and leaves a cell Make clear connections between various vocabulary words and concepts

to each other and to the purpose of the lab, so as to write a better Background Information Section.

Bio 9C: Monday, 12.6.10Title: Movement Across Cell Membranes – Day 3

Facilitated Diffusion When a substance diffuses

through a membrane by going through a protein channel

Regular diffusion goes through the lipid bilayer

New Vocabulary



Prote

in Ch

anne

l

Active Transport When a substance is pumped across a

membrane from where there’s a low concentration (less stuff) to where there’s a high concentration (more stuff)

Requires a pump (made of protein) and ATP energy!

New Vocabulary



Diffusion Across Cell Membranes:Review Background Information

Objectives for Class:• Implement an experiment to test diffusion of starch and glucose across a

membrane

Background Information Brainstorm•

Color Change?

Diffusion Across Cell Membranes:Presenting the Data/ Results



Water and Iodine


Bag Turned Purple/ Black No Color Change to

the Water

Glucose Test Strip changed color

Remember:Selective Permeability In Action: http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm



Work in your groups to explain what your results mean. If there are color changes, state

was this means in terms of what substances are present, but

DO NOT explain why the substance is where it is (this should go in the conclusion section)

Water and Iodine


Objectives for Class:• Use scientific vocabulary to explain how a cell membrane controls what enters and

leaves a cell• Make clear connections between various vocabulary words and concepts to each other

and to the purpose of the lab, so as to write a better Background Information Section.

Diffusion Across Cell Membranes:Data Analysis

Homework:Finish Typing/ Revising the Lab Report:

Final Copy Due Thursday w/ Rubric! Do Now:

Take out the Typed Background Information Section of the Denatured Enzymes Lab Report

Today’s Objectives: Use scientific vocabulary to explain how a cell membrane

controls what enters and leaves a cell Make clear connections between various vocabulary words

and concepts to each other and to the purpose of the lab, so as to write a better Background Information Section.

Bio 9C: Tuesday, 12.7.10Title: Movement Across Cell Membranes – Day 4




Writing Better Background Information Sections

Task I: Read the to example Background Information

sections from the Denatured Enzyme Lab and grade them according to the rubric.

Discuss the grading


leaves a cell• Make clear connections between various vocabulary words and concepts to each

other and to the purpose of the lab, so as to write a better Background Information Section.


Task II: Whole Class Create a mind-map to connect

the vocabulary and concepts for the Background Information Section. This will help us outline this section for us as well.





Task III: Use mind-map/

outline to re-write your background information section more effectively.

Revise Background Information Section

Complete all sections of the Lab Report

Water and Iodine





Diffusion Across Cell Membranes:Complete Lab Report

Homework: Do Now: Today’s Objectives:

Bio 9C: Wednesday, 12.8.10Title: No Class – Half Day

Documents

Homework: