Phospholipids Between Us: (Part 1) Understanding Membranes Eths Netlogoweb
Time: 2 Class periods (45 minutes each)
Level: All high school levels of Biology
Lesson OverviewThis activity allows students to qualitatively understand the dynamics of membrane formation. Students will use computational tools to alter concentration of water and lipids, and attractive and repulsive forces between the molecules to observe the effect on the resulting structure.
Developed by Kai Orton, PhD and Apurva Naik, PhD in association with the Center for Connected Learning (ccl.northwestern.edu)
Modified by Sugat Dabholkar for online implementation
Students will visualize the steps that lead to formation of lipid bilayers.
Students will observe interactions between phospholipids and water molecules.
Students will be able to explore conditions that favor or prevent cell membrane formation.
Materials and Tools
A computer lab or student computers with interne access and NetLogo installed
Clock or timers
Supplementary materials or handouts as instructor sees fit
Student computers should have the latest version of NetLogo installed
The instructor should be familiar with the activity, preferable running it before hand to better understand pitfalls and more difficult areas of the activity.
Students should have previous knowledge of:
Properties of water
Parts of a cell and cell compartments
Difference between a cell wall and a cell membrane
For exploration 4b, students may want to try to set water-water force and/or water-oil force to the extreme. In real cells, this will never be the case. In case some students still want to try these out, you can explain the physical significance of the following extremes:
|w-w force||w-o force||physical significance|
|0||-2||two immiscible liquids. They will form two separate layers|
|2||0||two miscible liquids. They will form a solution|
The structures that students might observe in the different simulations that they setup throughout this lesson may appear as a phospholipid bilayer, a micelle or a liposome. These structures mimic the same structures in a cell (phospholipid bilayer and liposome) and its compartments:
Phospholipid bilayer: outer cell membrane, nuclear membrane, Endoplasmic reticulum
Liposome: lysosomes food vacuoles
A third structure students might observe is a micelle (see figure below), which forms when lipids enter an aqueous environment such as with oil and water. A micelle forms when hydrophilic heads pack against each other protecting the hydrophobic tails in the micelle center.
- Life Science
- [HS-LS1] From Molecules to Organisms: Structures and Processes
Computational Thinking in STEM
- Modeling and Simulation Practices
- Using Computational Models to Find and Test Solutions
- Using Computational Models to Understand a Concept
- Systems Thinking Practices
- Investigating a Complex System as a Whole
- Thinking in Levels
- Understanding the Relationships within a System
- Data Practices
- Analyzing Data
- Collecting Data