7th Grade PPP#3 Dialysis Tubing Exploration Osmosis and Diffusion NGSS–MS-LS1-2 Develop and use a model to describe the function of a cell was a whole and ways parts of the cells contribute to the function

Diffusion Exploration - Day 1 OBJECTIVE: (NGSS MS-LS1-2): Develop and use a model to describe the function of a cell was a whole and ways parts of the cells contribute to the function Do Now: Pick up Journal from front table Sit with Buddy #1…have a new DO NOW page ready. Today: Dialysis Tube Investigation Journal Prediction(s) and Observations Plan YOUR investigation with your Buddy Do Later: Anything unfinished in your notebook!

Diffusion Exploration - Day 2 OBJECTIVE: (NGSS MS-LS1-2): Develop and use a model to describe the function of a cell was a whole and ways parts of the cells contribute to the function Do Now: Same Buddy…have DO NOW page ready. Today: Lab Safety Rules Review YOUR investigation Class notes/OBSERVATIONS Do Later: Anything unfinished in your notebook!

Diffusion Exploration - Day 3 OBJECTIVE: (NGSS MS-LS1-2): Develop and use a model to describe the function of a cell was a whole and ways parts of the cells contribute to the function Do Now: Same Buddy…have DO NOW page ready. Today: Vocabulary and Concepts Proof = Analysis of Evidence Analogy to Cell parts Do Later: Anything unfinished in your notebook!

Diffusion Exploration - Day 4 OBJECTIVE: (NGSS MS-LS1-2): Develop and use a model to describe the function of a cell was a whole and ways parts of the cells contribute to the function Do Now: Same Buddy…have DO NOW page ready. Today: Online Simulation C.E.R. Lab Reports Journal – “Rough” C.E.R. for Diffusion Explorations Do Later: Anything unfinished in your notebook!

Diffusion Exploration - Day 5 OBJECTIVE: (NGSS MS-LS1-2): Develop and use a model to describe the function of a cell was a whole and ways parts of the cells contribute to the function Do Now: Same Buddy…have DO NOW page ready. Friday Funnies Today: FINAL DRAFT C.E.R TBD: Reading Assignment // TBD: Video Do Later: Anything unfinished in your notebook!

Give 2 examples of a phenomenon (one ex is thunder & lightning) Please grab your journal from the FRONT Sit with your Number 1 Science Buddy Do Now: What is a phenomenon? Give 2 examples of a phenomenon (one ex is thunder & lightning)

Dialysis Tube Investigation

Prediction Observe the demonstration Make a prediction in your journal about what you think may happen. You can make more than one prediction. Wait for 15 minutes

Model of the system BEFORE AFTER

Our predictions

Observations What did you notice? What happened to the substances in the cup? In the tube? Keep discussing until someone says something like, “there must be little holes in the tube that stuff goes through” and introduce the words “diffusion” and “semi-permeable membrane”

Potential Question to investigate: Have them brain storm “testable questions” until you get someone to say, “What stuff can pass through the tube?” and “what causes the blue color change?”

Planning Investigation: Choose one of the two questions to attempt to answer in your own investigation (as a pair) Plan your investigation (state the steps including amounts of materials) Develop a way to collect data Tomorrow you will: Run your investigation Gather your data Come to a conclusion/claim Materials Dialysis Tubing Glucose/Starch Solution Iodine Solution Pipet Water Cups Glucose Test Strips Well plate

Tuesday DO NOW: Name 3 safety rules that will be needed for today’s investigation. Now its time to run your investigations!

Our Observations/Data (i = iodine, gs = glucose/starch, w = water) Your names In tube In cup What happened? Grayson/Lippincott Gs I & w Cup clear, tube blue Collect the entrie classes data as they finish have them come up

Wednesday Do NOW:

Class conclusions from our observations This will be Wednesday, you will have to display the data table 2 slides back

Phenomenon: When a dialysis tubing bag filled with glucose/starch solution is placed in an Iodine solution, certain substances will pass through the tubing while others will not. Copy down

Important terms/notes Diffusion: movement of molecules (through a cell membrane) from a higher concentrated area to a lower concentrated area Osmosis: water moving into and out of a cell (from an area of higher concentration to an area of lower concentration) Equilibrium/Homeostasis- both areas, inside and out of the cell, have an equal concentration of molecules Semi-permeable membrane: a membrane that allows certain substances through while blocking other substances Iodine + starch = a blue color (bc Iodine is an indicator of starch) Copy into journal

Did it diffuse? Proof (how do you know) Iodine Glucose Starch Water Answers on next slide

The iodine solution went from a darker color yellow to a clear color. Did it diffuse? Proof (how do you know) Iodine Yes The iodine solution went from a darker color yellow to a clear color. When iodine passed into the bag, it met with the starch and turned blue Glucose No The glucose stayed in the bag. I know this because we tested the cup’s solution with a glucose test strip and it came out negative for glucose. Starch If the starch did diffuse, then the solution in the cup would have turned blue. Water They initially put 300 mL of water into the cylinder, but now there’s only 220 mL left Initially, 60 mL of glucose starch solution into tube. After, there was about 65 mL of solution in the tube.

Analogy Map IN REAL LIFE IN THE CELL Dialysis Tubing Glucose/Starch Solution Cup (Iodine/Water)

Thursdays DO NOW

Online simulation to understand diffusion: https://concord.org/stem-resources/diffusion What to answer in journal: After: Collect Data 1, answer the multiple choice After: Collect Data 2, answer: “How did the rate of diffusion change with a higher temp” After: Collect Data 3, answer: “How did diffusion of the perfume change with an increase of concentration?” Analysis: Answer #1&2 DO this Thursday before Rough CER

Our question is…. Which substances passed through the membrane? Which substance did not? Use data to support your claim.

Rough CER CER Rough Draft Claim: Which substances were able to diffuse through the dialysis tube and which were not? Evidence: What data did you or the class collect that led you to this claim? Reasoning: What is the science behind this phenomenon? Include all relevant key terms. Friday will be final CER