Learning Guide: The Cell Membrane and Passive Transport
Bill Activity #24
To Think About: How is growth and dynamic homeostasis maintained by the constant movement of
molecules across membranes?
1st Read About: Membrane structure and function
Pgs. 125-130 Campbell’s Biology 9th edition (2-sided column notes)
 Cellular membranes are fluid mosaics of lipids and proteins
o Describe why the cell membrane exhibits selective permeability
o Explain why a phospholipid is considered amphipathic (use a sketch in your answer).
o Describe the fluidity of cell membranes.
o Using the components of the cell membrane, explain why the cell membrane is
referred to as a “fluid mosaic model”. Describe how each of the following can affect
membrane fluidity: a) decreasing temperature, b) phospholipids with unsaturatured
hydrocarbon chains, c) cholesterol
o Explain using an example how variations in the cell membrane lipid compositions can
be an evolutionary adaptation
o Membrane proteins are the mosaic part of the model. Describe each of the two main
categories: integral proteins and peripheral proteins.
o Membrane carbohydrates are important in cell-cell recognition. What are two
examples of this?
o Distinguish between glycolipids and glycoproteins.
2nd Interact: Watch Mr. Andersen’s 015 Cell Membranes Video. Take notes in your bill.
o In the context of cell membranes, explain why Mr. Andersen uses shampoo as a
chemical component in his DNA extraction experiment.
3rd Read About: Membrane structure results in selective permeability
o Pgs. 131-135 Campbell’s Biology 9th edition (2-sided column notes)
o Explain how the biological membrane is an example of a supramolecular structure.
Include an explanation of the cell membrane’s most important function. Sketch a
muscle cell and show all of its chemical exchanges with labeled arrows to further
enhance your answer.
 The permeability of the lipid bilayer.
o Create the two column table with the headings (material and method). Consider the
following materials that must cross the membrane. For each tell how it is
accomplished: carbon dioxide, glucose, H+, oxygen, water
o Describe the structure and function of transport proteins.
 Passive transport is diffusion of a substance across a membrane with no energy investment
o Define and take notes on the following terms as you read: diffusion, concentration
gradient, passive transport
o Describe how water diffuses across the membrane. Name this movement.
o Sketch animal cells and plant cells in three types of solutions. Label the solution types,
and their effects on the cells. Take notes about these cell conditions as you read.
o Define osmoregulation and P. caudatum’s evolutionary adaptation.
o Define facilitated diffusion. Is it active or passive transport? Cite two examples.
4th Interact: Watch Mr. Andersen’s 016 Transport Across Cell Membranes Video. Take notes on the video .
Supplementary Resources: Click the links below for more information to help you learn more about this
lesson.
 BFW Publishers: Principles of Life Chapter 5 Online Resources
 Crash Course Biology: In Da Club—Membranes and Transport
 Pearson BioCoach: Membrane Structure and Transport
 Pearson BioCoach: Membranes and Communication
 McGraw Hill: Osmosis
 Georgia State University Hyperphysics: Diffusion and Osmosis (from a physicist’s point of view)
 Wisc-Online: Passive Transport-Osmosis (simulation)
 Northland College: Active Transport Animation
Learn More: For more information about membrane structure and function, use the links below:
 OsyOsmosis: A game that allows you to control a character, Osy, by controlling how much water
she takes up from her environment
 Nobel Prize in Chemistry, 2003: Peter Agre and Roderick MacKinnon, “for discoveries concerning
channels in cell membranes.”