What are living things made of ?
Teacher Resources
Learning Targets
Learning Experiences
Phospholipid & Membrane Transport — 3D Molecular Designs (for purchase) Foam model phospholipids and cell membranes. This kit will be distributed at GREAT workshops 2016/17. www.hudsonalpha.org/GREAT Build-A-Membrane — Genetic Science Learning Center Using paper cut-outs and a box top, students build a model of a cell membrane. bit.ly/build-a-membrane Cell Membrane Tutorial — Genetic Science Learning Center
25 I can build a model of a phospholipid and compare the chemical characteristics of the two distinct parts of the molecule. (1) 26 I can build a model of a cell membrane and use the model to demonstrate how materials move across the membrane. (2, 5) 27 I can distinguish between solution types based on solute concentration (hypo-, hyper-, isotonic solutions). (5) 28 I can investigate how materi- als move across membranes and categorize the movements as active or passive transport. (5) 29 I can investigate cell membrane function using data collected from my investigation to explain a phenomenon related to movement across a membrane. (2, 5) 30 I can compare active and passive transport, provide examples of each, and describe
This series of activities highlights the chemical structure of the phospholipid membrane and the various ways large and small molecules move between the inside and outside of the cell. Students construct a model of a single phospholipid to illustrate how this macromolecular building block possesses both hydrophobic and hydrophilic properties. Students expand the model to form a phospholipid bilayer membrane. This membrane model is revisited and revised several times during the course. The function of the membrane is investigated using laboratory experiments, web-based simulations, or simple diagrams. Use activities from the resource list. By embedding various proteins within their membrane models, students can demonstrate how biologically important materials move across the membrane. Students use the models to demonstrate how the movement of water is a cellular response to different solute concentrations within and outside the cell (hypo-, hyper-, and isotonic conditions). Students link these membrane transport responses to the properties of water introduced in learning targets #3 - 7, and explain how water movement is critical to the maintenance of homeostasis for cells and vascular systems. Students also model how small and large molecules are transported across the membrane, differentiating between active and passive methods of transport. Students provide examples of each and discuss specific transport mechanisms such as aquaporin, the sodium/potassium pump, and calcium channels. Utilizing standard experimental design parameters and materials provided by the instructor, students plan and carry out an investigation to illustrate a specific form of membrane transport (examples are included in the resource list). Collected data and conclusions are shared with classmates.
Teacher Tip Teachers may wish
Reading passage about cell membranes. bit.ly/cell-membrane-tutorial Homeostasis (and the Cell Membrane King) — Science with the Amoeba Sisters Vidoe clip on homeostatsis bit.ly/cell-membrane-king Diffusion Confusion — NMSI Laying the Foundation Lesson Osmosis lab using both dialysis tubing and potatoes to explore osmosis. Onion Cell Diffusion — Alabama Science in Motion C2aOnionDif Exploring effect of salt concentration on purple onion cells. bit.ly/AMSTI-ASIM
to keep and store a class set of membrane models. These same models will be used further in the learning progression.
Rubber Egg Diffusion — Alabama Science in Motion C2cEggDif This is a traditional egg osmosis lab where the shell is dissolved and students observe osmosis and record data daily. Note: To more closely address the standard, allow students to alter key variables to produce their own data. bit.ly/AMSTI-ASIM Osmosis and Diffusion — Alabama Science in Motion C2bOsDif Osmosis lab using potato slices can also be adjusted to provide opportunities for student experimentation. bit.ly/AMSTI-ASIM
Diffusion Across Biological Membranes: A Simulation — Cornell Institute for Biology Teachers A multi-part Inquiry Diffusion Lab for student experimentation. bit.ly/diffusion-across-membranes
the process for each. (2, 5) 31 I can relate multiple
properties of water to impacts on cells and living systems, as well as the maintenance of homeostasis. (2, 5a)
These activities could be demonstrations or brief investigations that set the stage for student designed experimentation. Sample investigations include:
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• Examine the process of diffusion and osmosis through a selectively permeable membrane. • Explore the change in the mass of a potato piece through the process of osmosis depending on the concentration of corn syrup. • Use two different sizes of dialysis tubing to represent cellular and organelle membranes. Students place solutions of iodine, starch, and glucose on different sides of a membrane to show movement of molecules.
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A Field Guide to the Alabama Standards
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The Biology Compendium
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