Getting Students Through The Cellular Membrane

Workshop Learning Objectives Educators attending this workshop will: Utilize tools that can support the NGSS student learning outcomes of three dimensional lesson design including - Water Kit© to model the polar nature of water Phospholipid Modeling Set© to observe the similarities and differences in phospholipid structure Phospholipid and Membrane Transport Kit © to construct and cross the cell membrane 3D Printed Models to transfer between various model types Learn something new and interesting that is for your own professional development. HAVE FUN!

Workshop Learning Objectives What NGSS dimensions will be targeted? SEPs CCCs DCIs Asking questions Patterns PS1.A: Structure and properties of matter Developing and using models Cause and effect PS1.B: Chemical reactions Constructing explanations Scale, proportion, and quantity LS1.A: Structure and function   Structure and function LS1.C: Organization for matter and energy flow in organisms

What does the Empire state building have to do with water? https://en.wikipedia.org/wiki/Empire_State_Building#/media/File:Empire_State_Building_by_David_Shankbone_crop.jpg http://www.riskologyconsulting.com.au/the-simple-solution-in-a-water-glass/

What does the Empire state building have to do with water? On this planet, in one day, ~ 200 million work hours are consumed by women collecting water for their families This amount of time is equivalent to building 28 Empire State Buildings every day! http://www.pbs.org/wgbh/buildingbig/wonder/structure/empireconstr1_skyscraper.html http://www.deccanchronicle.com/world/america/300816/women-girls-spend-200-million-hours-collecting-water-unicef.html

the characteristics of water Exploring the characteristics of water Spill your water cup!

Explore the Water Cup 1. Show me a physical representation of water. How do you know which model represents a water molecule? What color represents the oxygen? Which atoms stick to each other? Why do water molecules stick to each other?

the characteristics of water Explaining the characteristics of water Water is POLAR! classconnection.s3.amazonaws.com

the characteristics of water Explaining the characteristics of water Results in hydrogen bonding between water molecules! classconnection.s3.amazonaws.com

Elaborating On solubility Does this molecule interact with water molecules? HYDROPHOBIC ETHANE

MOLECULAR MANIPULATION Elaborating On solubility MOLECULAR MANIPULATION

Elaborating On solubility ETHANOL! Does this molecule interact with water molecules? HYDROPHILIC

Elaborating On solubility Question: How long does the hydrophobic tail have to be before it overwhelms water’s interaction with the alcohol group? How would your students design a lab to find out?

Getting through the cell membrane How does a polar molecule, like water, diffuse through a largely hydrophobic bilayer?

Getting through the cell membrane To answer this question we need to know something about phospholipids . . . Examine the phospholipid molymod at your table. 1. Describe or illustrate the overall structure of your model. 2. What atoms are present in your model and what color represents each of these atoms? 3. What other observations or questions do you have about your model? 4. Compare and contrast your group’s phospholipid to another group’s phospholipid. 5. Make note of any similarities or differences. Speculate why a cell membrane would have different phospholipids.

Focus on Phospholipid Heads Phosphatidylcholine Sphingomyelin The Outer Leaflet

Focus on Phospholipid Heads Phosphatidylethanolamine Phosphatidylserine Phosphatidylinositol The Inner Leaflet

Focus on Phospholipid Tails Hydrogens in the cis configuration Produces a larger “kink” in the tail

Focus on Phospholipid tails Hydrogens in the trans configuration Produces a smaller “kink” in the tail

Constructing A Phospholipid

Constructing A Phospholipid Step 2: Remove the hydroxyl (OH) group from a sat. fatty acid. Step 3: Join your glycerol and fatty acid. Step 1: Remove one of the hydrogen (H) atoms from the glycerol.

Constructing A Phospholipid Step 5: Remove another hydrogen (H) from the glycerol. Step 6: Repeat the process with the unsaturated fatty acid. Step 4: Combine the H and the OH to form water.

Constructing A Phospholipid Step 7: Remove the final H from the glycerol and the OH from the phosphate. Combine the H and the OH. Attach the phosphate to the glycerol backbone. Phosphate + =

Transition between Multiple Models!

building the cell membrane Through A Series of Gedanken Experiments! First Thought Experiment: How would ten phospholipids need to be arranged to form a film at the top of a beaker of water?

building the cell membrane Through A Series of Gedanken Experiments! Second Thought Experiment: How would the ten phospholipids need to be arranged in order to be submerged in a beaker of water?

building the cell membrane Through A Series of Gedanken Experiments! Third Thought Experiment: How would the phospholipids need to be arranged if they were to be submerged AND contain water? (You may use as many phospholipids as needed in the kit.)

crossing the cell membrane How does a polar molecule, like water, diffuse through a largely hydrophobic bilayer?

crossing the cell membrane It gets by with a little help from its friend. . . AQUAPORIN!

crossing the cell membrane Investigating channels! GLUT Carrier Protein Aquaporin Gated Potassium Channel Potassium Leak Channel Sodium-Potassium Pump

crossing the cell membrane Investigating channels! Passive Transport: Aquaporin K+ Leak Channel

crossing the cell membrane Investigating channels! Active Transport: Sodium-Potassium Pump

crossing the cell membrane Investigating channels! Active Transport: 1. Sodium binds on intracellular side. 2. The pump is phosphorylated by ATP. 3. The pump shape changes, exposing the sodium to the extracellular space.

crossing the cell membrane Investigating channels! Active Transport: 4. Binding affinity changes to release Na+, and take in K+. 5. Phosphate detaches. 6. Original shape is restored, releasing K+ into the cell.

THANK YOU! For more molecular stories. . . Come visit us at booths 419 and 421! We hope to see you soon!

crossing the cell membrane Investigating channels! Passive Transport: Gated Potassium Channel

crossing the cell membrane Investigating channels! Passive Transport with a Carrier Protein: Glucose Transporter 1 (GLUT1)

crossing the cell membrane Investigating channels! Use the GLUT Carrier Protein to model passive transport with a carrier protein.