Movement Across cell Membranes

Movement Across cell Membranes Moretti and Dickson

Bio 9D: Thursday, 12.2.10Title:Movement Across Cell Membranes – Day 1 • 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. • Do you want to share a slide or paragraph from your digestion story with the class? If so, write down exactly which slide or paragraph you would like to share. • Take out the project rubric and the project if it’s printed.

Today’s Agenda & Objectives • Update on Class Contract: • We are still going strong to get Round 2 of cookies on Monday • One strike earned on Tuesday • No strikes earned yesterday • No Class Contract violations • Let’s make today great so we can stay on track! • Objective: Moving on to a new unit • SWBAT design an experiment to test which molecules can pass through a cell membrane (drawing on knowledge of glucose, starch, and chemical indicators)

Today’s Agenda & Objectives • Objective: Moving on to a new unit • SWBAT design an experiment to test which molecules can pass through a cell membrane (drawing on knowledge of glucose, starch, and chemical indicators) • Agenda: • Quick sharing of Digestion Projects (10 min max) • Review Do Now (5 min max) • Experiment Design (30 min)

Designing a Lab: Diffusion Across Cell Membranes 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 Model Cell w/ Dialysis Tubing Membrane Starch & Glucose Solution Water • 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.

Bio 9D: Friday, 12.3.10Title:Movement Across Cell Membranes – Day 2 • No Homework! • 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?

Check-In from Yesterday • We didn’t get to a contract violation, BUT… • It was clear that someone was saying inappropriate things (maybe more than one person?) • This gets in the way of our progress towards having an excellent class • On the small piece of paper, write: • The inappropriate things that were said in class yesterday • Which person or people said them • Any other thoughts you have about this. Everyone must write something down.

Today’s Objectives & Agenda • Describe and explain the following terms: • Lipid Bilayer • Selective Permeability • Concentration • Diffusion • Use this vocabulary to: • Explain how a cell membrane controls what enters and leaves a cell • Design an experiment to test whether glucose and/or starch can pass through the cell membrane Agenda: • Notes/Discussion/Quick Animation • Cell Membrane Experiment: • Purpose & Hypothesis (discuss as class) • Set up – Demo, then do it in your group • Summarize procedure & make data table • Collect data

Cell Membrane Vocabulary • Lipid Bilayer • Two layers of lipids that form the outer membrane of a cell. • Flexible • Strong • Do not Dissolve in water zoom out • Image to the right shows the lipid bilayer of a cell. Notice how it has other components like protein channels & “pumps” built into it. • Objectives for Class: • Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

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

Cell Membrane Vocabulary Diffusion • 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 • Objectives for Class: • Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

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

Designing a Lab: Diffusion Across Cell Membranes Purpose of the Experiment: To figure out whether the cell membrane will allow glucose, starch, or both to pass through the membrane? Hypothesis: (write your prediction on the lab handout) • 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.

Designing a Lab: Diffusion Across Cell Membranes Review Experiment Set-Up: • 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 • 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.

Designing a Lab: Diffusion Across Cell Membranes Procedure Overview: • 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 • Put dialysis bag into beaker with water and iodine • Part II: Wait 30 min to allow for substances to move across the membrane Starch & GlucoseSolution 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.

Jackson Carlheb Devon Samantha Hannah Loveng Miguel Lorreno Rayoni Trae Nick Owen Marcelo Joas Dyani Davnys Christine Nekeyla Courtney Kayla

Bio 9D: Monday, 12.6.10Title:Movement Across Cell Membranes – Day 3 • Homework: Type up all sections of lab report except for Background Information • Silent Do Now (in notebook w/ title & date) • Take out your Diffusion Lab packet • Look at your data table w/ your results • 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?

Today’s Objectives & Agenda • Discuss and analyze the results of the diffusion experiment in order to… • Draw conclusions about which substances diffused across the membrane Agenda: • Quick Class Discussion & Revisit the Animation • Typing Time

Diffusion Across Cell Membranes: Presenting the Data/ Results • Color Change? Glucose Test Strip changed color Bag Turned Purple/ Black Starch & GlucoseSolution No Color Change to the Water Remember: Selective Permeability In Action: http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/Osmosis_Animation.htm Water and Iodine • Objectives for Class: • Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

Lab Report Typing Step 1: Set up the Title of your lab report with all required info Step 2: Set up section headings in order for all sections of your lab report Step 3: Skip Background Info for now. Step 4: Start typing whichever other section is easiest for you to start on right now. All sections except Background Info should be typed by tomorrow. Work quietly, talking with your lab partner only. No internet use allowed until last 5 minutes of class (for emailing work).

Bio 9D: Tuesday, 12.7.10Title:Movement Across Cell Membranes – Day 3 • Homework: Write the Background Info section of your lab report • Silent Do Now (not in notebook!) • Take a napkin and a brownie! • For the next round of treats we will raise the expectations even higher! Do you think we should do this by…(answer on index card) • Making the standards for class behavior higher (fewer strikes, more anti-strikes for focused behavior required) • Making the length of time longer (two weeks without breaking contract) 3. On the handout: Read, evaluate, and write strengths & weaknesses for Example 1 and Example 2

Today’s Objectives & Agenda • Write an excellent Background Info section of a lab report • Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections • Write explanations and connections for all important terms and concepts for the Diffusion Lab background info • Agenda: • Evaluate examples of Background Info • Class discussion • Organize info for Diffusion Lab Background Info

Sample Background Info sections Example 1 Example 2 Strengths:good knowledge of vocab words; made sure the reader understood the key terms Things to improve: using the key terms to connect to the lab; more like a list of definitions; opening sentence could be more engaging; take out words like : “here’s what you need to know” Overall grade:15/20…. C  rass Strengths: They explained things well, they gave examples of chemical equations, they have proper formatting, the diagrams are a good explanation for a bunch of vocab words. They connect the key terms to the lab. more _______ Things to improve: explain monosaccharide and polysaccarides better. Overall grade: 18 out of 20 8] B] Objectives for Class: Use the lab report rubric to identify mediocre versus excellent examples of Background Info sections

Diffusion Lab Background Info • You have 7 minutes to complete the explanations for each term listed, plus at least 2 others • Do this by referring to your notes • Work quietly, stay focused on the task, and be productive! Connections between words…

Bio 9D: Wednesday, 12.8.10Title:Cell Membranes Wrap-Up • Homework:Complete lab report due tomorrow – typed, printed, stapled, ready to hand in w/ rubric @ start of class. • Silent Do Now (in NB w/ title and date) • Write down what you understand about diffusion and concentration (check your notes for reminders). What are they and how to they relate to each other? • What is an example of diffusion that you have seen in everyday life?

Today’s Objectives & Agenda SWBAT… • Define and illustrate 4 ways that substances can move across cell membranes • Diffusion, osmosis, facilitated diffusion, and active transport • Explain when each process would be used for materials entering a cell Agenda: • Notes/Discussion on Vocabulary • We are going to hold “tangent” questions until the end today! • Review Questions (Worksheet) Remember: Earn treat-points for sustained productive class. Strikes for side conversations that interrupt class (3 per class starts the treat-cycle over)

Cell Membrane Vocab Review Diffusion • Concentration • How much “stuff” is in a given amount of liquid • 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 Osmosis • Objectives for Class: • Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

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

Cell Membrane Vocabulary • 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! • Objectives for Class: • Use scientific vocabulary to explain how a cell membrane controls what enters and leaves a cell

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

Movement Across cell Membranes