1. MOVEMENT ACROSS CELL MEMBRANES Moretti and Dickson

2.  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.  Silent Do Now: (in your notebook w/ title & date) Which molecule is bigger, starch or glucose? Explain with a diagram in your notebook. When you’re done, take out your Digestion Project and make sure it is ready to hand in! Bio 9A: Wednesday, 12.1.10 Title: Movement Across Cell Membranes – Day 1

3. Today’s Agenda & Objectives  Objectives:  Design an experiment by drawing on your knowledge of starch, glucose, cell membranes, and experimental indicators that test for the presence of starch and glucose.  Agenda:  Quick sharing of Digestion Projects (10 min max)  Review Do Now (5 min max)  Experiment Design (30 min)

4. 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 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

5. Yamile Erick AmritaLila Kenny Cassandra HajarMartely Imani Olivia Martin Bryan Nathy Javier Devin Lorena Alerte Lennin Victor Joshua Daysia Emiliano Jesse Joelle Naidaliz Beverly

6.  Homework: Rough draft of Background Info and Purpose & Hypothesis sections for a lab report on the membrane experiment (refer to the handout from yesterday) Type and print or bring a handwritten copy to class tomorrow!  Silent Do Now (in NB w/ title & date)  What is happening to the dye in the water?  What vocabulary word from last night’s reading applies to this situation? Why?  What do you think will happen to the dye by the end of class? Bio 9A: Thursday, 12.2.10 Title: Movement Across Cell Membranes – Day 2

7. Today’s Objectives  Describe and explain the following terms:  Lipid Bilayer  Selective Permeability  Diffusion  Osmosis  Use this vocabulary to explain how a cell membrane controls what enters and leaves a cell Agenda:  Notes/Discussion/Quick Animation  Ticket To Go  Plan lab procedure w/ partner

8.  Lipid Bilayer  Two layers of lipids that form the outer membrane of a cell. Flexible Strong Do not Dissolve in water Cell Membrane Vocabulary Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell 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

9.  Selective Permeability  When a membrane only allows certain substances to pass across the membrane (and not others)  Substances usually pass across based on the size, shape, and charge (+/-/neutral) of the molecules New Vocabulary Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

10.  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 concentration Note: 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

11. Diffusion, Osmosis and Selective Permeability In Action: http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm New Vocabulary Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

12. Ticket to Go On your small piece of paper:  Draw one picture that illustrates at least 3 of the words we’ve talked about today  Lipid Bilayer  Selective Permeability  Concentration  Diffusion  Osmosis  Write the words on the picture so I know which ones you’re drawing If you’re done early: Take out the lab handout for tomorrow and work w/ your partner to start planning your procedure

13.  Homework: None!  Do Now: Take out the Diffusion Lab Handout. With your partner from Wednesday, talk QUIETLY to discuss and fill in the Procedure Overview (Parts 1-4) on the back of this handout. You have 10 minutes to complete this. Today’s Objective: Design, conduct, and analyze data from an experiment to determine which substances (glucose and/or starch) can pass through a cell membrane. Bio 9A: Friday, 12.3.10 Title: Movement Across Cell Membranes – Day 3

14. Yamile Erick AmritaLila Kenny Cassandra HajarMartely Imani Olivia Martin Bryan Nathy Javier Devin Lorena Alerte Lennin Victor Joshua Daysia Emiliano Jesse Joelle Naidaliz Beverly

15. Do Now #2 – In your notebook Title for Today: Diffusion Lab 1. Summarize the purpose of this experiment: 2. Write a specific prediction for this experiment:

16.  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  Put dialysis bag into beaker with water and iodine Diffusion Lab: Procedure Review – Part 1 Water and Iodine 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. Starch & Glucose Solution

17.  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 Diffusion Lab: Procedure Review – Part 3 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.

18. Do Now #3  In your notebook, create a data table for this experiment!  Your table must include a place to record beginning and ending colors of:  The water/iodine in the beaker  The dialysis bag (“cell”)  The glucose test strip

19. Kenny Yamile LenninMartin Amrita Javier LorenaLila Emiliano Nathy Jesse Hajar Bryan Victor Martely DaysiaDevin Naidaliz Joshua Joelle Cassie Beverly Erick Olivia 9A – Same seats as last week! ImaniAlerte

20.  Homework: Revise Background Info if necessary; continue with other sections of lab report (whole thing due Thursday)  Silent Do Now (in notebook w/ title & date)  Find your Diffusion Lab data table  Summarize your results in your notebook and try to explain what each result means. Was there a color change in the beaker? What does this tell us about a substance that did or did not diffuse? Was there a color change in the bag? What does this tell us? Was there a color change in the glucose test strip? What does this tell us? Bio 9A: Monday, 12.6.10 Title: Diffusion Lab – Day 2

21. Today’s Objectives & Agenda  Discuss and analyze the results of the diffusion experiment  Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections  Identify the strengths and areas for improvement in your own background info section  Agenda:  Quick Class Discussion of Results  Evaluate examples of Background Info  Class discussion & brainstorm

22.  Color Change? Diffusion Across Cell Membranes: Presenting the Data/ Results Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell Water and Iodine Starch & Glucose Solution Bag Turned Purple/ Black No Color Change to the Water Glucose Test Strip changed color

23. Today’s Objectives & Agenda  Discuss and analyze the results of the diffusion experiment  Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections  Identify the strengths and areas for improvement in your own background info section  Agenda:  Quick Class Discussion of Results  Evaluate examples of Background Info  Class discussion & brainstorm  Peer editing

24. Lab: Diffusion Across Cell Membranes Writing Better Background Information Sections Objectives for Class: Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections Task 1 – Do this silently on your own: Read the two example Background Information sections from the Denatured Enzyme Lab Grade them according to the rubric. Identify strengths and areas for improvement

25. Sample Background Info sections Strengths: gives exact definitions, defines all the words, necessary for understanding the lab Things to improve: do not give examples, not detailed, needs a paragraph, flow, no creativity, seems robotic, definitions were not explained well Overall grade: ¾ or 15/20 or C Strengths: it’s flows like a river It gave examples, they avoided phrases like “a word you need to know is blahblblah” they included every definition. They included the concept/idea. Things to improve: don’t use technical words. It doesn’t give a one sentence overview of the lab Overall grade: 4/4 A or A+ Example 1 Example 2 Objectives for Class: Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections

26. Lab: Diffusion Across Cell Membranes Writing Better Background Information Sections Objectives for Class: Identify the strengths and areas for improvement in your own background info section Task 2 – Do this silently on your own: Trade Lab Reports with your partner (5 min) Read their Background Info and identify… Does it start with a logical and meaningful topic sentence? Does it make strong connections between sentences? Between words? Does it explain many important terms and concepts necessary for understanding the lab? Does it avoid phrases like “what you need to know is…” Write down the strengths and areas for improvement on your partner’s background info section. Take 2 minutes per partner to explain and give feedback

27.  Homework:  Finish Cell Membrane worksheet if not finished in class  Completed, typed, printed lab report due Thursday  Silent Do Now (in notebook w/ title & date)  Look back at your vocab notes from last week 1.Compare and contrast diffusion and osmosis How are they similar? How are they different? 2.What do you understand about facilitated diffusion? How is it different from regular diffusion? 3.What do you know about active transport? Bio 9A: Tuesday, 12.7.10 Title: Cell Membranes Wrap-Up

28. Today’s Objectives & Agenda SWBAT…  Define and illustrate diffusion, osmosis, facilitated diffusion, and active transport  Explain when each process would be used for materials entering a cell Agenda:  Notes/Discussion: Facilitated Diffusion & Active Transport  Review Questions Note: Thanks for your feedback at the end of class yesterday. We will discuss this further in class on Thursday.

29.  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 concentration Vocabulary Review Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell Diffusion Osmosis

30.  Facilitated Diffusion  When a substance diffuses through a membrane by going through a protein channel  Regular diffusion goes through the lipid bilayer New Vocabulary Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell Protein Channel

31.  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 Objectives for Class:  Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

32. Today’s Objectives & Agenda SWBAT…  Define and illustrate diffusion, osmosis, facilitated diffusion, and active transport  Explain when each process would be used for materials entering a cell Agenda:  Notes/Discussion: Facilitated Diffusion & Active Transport  Review Questions  Work on your own  Finish in class, otherwise for HW along w/ lab report