Lesson 4

Lesson Title: Passive and Active Diffusion State Standards: GLEs/GSEs LS1-1a Students will demonstrate an understanding by explaining the relationships between and amongst the specialized structures of the cell and their functions (e.g. transport of materials, energy transfer, protein building, waste disposal, information feedback, and even movement).

Context of Lesson: The lesson will help students to understand the transport of substances across a membrane. By the end of the lesson students will understand that a membrane can be selective of what substances cross it passively and can actively regulate other important substances.

Opportunities to Learn: Depth of Knowledge The lesson will be mainly level two where students are learning the new concepts of diffusion and passive vs. active transportation. There will be level three learning when students are asked to predict if they are creating a hypotonic or hypertonic situation with the net logos model.

Prerequisite Knowledge Students need to understand that polarity drives behavior.

Students need to understand diffusion can be both active and passive Students need to understand that membranes can be selective.

Plans for Differentiating Instruction We will be using a computer simulation model through Net logos. This will help the visual learner understand selective membrane and why pumps are necessary. The students will also see how a cell can become hypo/hypertonic.

Accommodations and modifications The work sheet I created for the Net logos program will have some key words highlighted in the questions to help guide the students to the correct answer. Having key words highlighted will aide the student in what to look for and what he/she should pay attention to.

Environmental factors The computer lab is a distraction if the students are not kept on track so as the teacher I will need to constantly be moving and maintain a line of sight on the computer monitors.

Materials -Microscopes -Slides -Salt -Onion -Net logos worksheet

-Net logos worksheet with guiding points included -Computer lab -I will need to download Net logos onto all of the computers prior to this day -Download the diffusion models before this day -Pre-test and review

Objectives: •

The students will demonstrate their knowledge of hypotonic vs. hypertonic on the worksheet with the net logos program.

•

The students will demonstrate their knowledge of passive vs. active transportation with the worksheet.

•

The students will demonstrate their knowledge of cells so far on the pre-test

Instruction: Opening: Last class I asked you to find out what kind of molecules you thought would need to be pumped into the cell for homework. I want you to write down what you found out last night on a piece of paper with you names on it. If you did not look it up last night, guess. You will get a bonus point on the test at the end of the week if you get it right. Teacher action: collect papers Have students volunteer to share what they found about active and passive diffusion. Guide them through questions to put together the rules for diffusion.

Use their rules to explain what active and passive diffusion are and how the cell uses them to survive.

Engagement: Now that the students understand the active and passive diffusion, we can transition into concentration gradients as the driving force of passive diffusion, and the effects of concentration gradients on a semi-permeable membrane. I want students to come to conclusions about what they believe a cell will do when it is hypotonic, isotonic, or hypertonic (this section of class should be in the computer lab so students have examples of hypotonic, isotonic, and hypertonic on the board to refer to during the activity) and put them on the board. Students will begin the Net logos program with a work sheet to test their predictions about the cell and see passive and active diffusion in action. If students finish the worksheet early, I will encourage them to use their notes to study for the pretest. I will have the students create the same onion slice slides from the last class for a hypertonic, hypotonic demonstration. Once the students have created two slides, I will have them create and observe both a hypotonic and isotonic solution and observe the effect on the cell. For the hypertonic solution, the students will add salt water to the cell and observe its effect. For the hypotonic solution, the students will do the same thing only using purified water.

Closure: We will head back to the classroom for the pretest, which I will promptly distribute. Students will take the test and hand it in. This will give me an understanding of what they get

and what they are struggling with so far. I will hand the test back next class. We will review it and that should act as both a review for the students and a study guide for the test.