1.3.U1:  Phospholipids form bilayers in water due to the amphipathic properties of phospholipid molecules.

• Draw a simplified diagram of the structure of the phospholipid, including a phosphate-glycerol head and two fatty acid tails.

• Define hydrophilic and hydrophobic.

• Define amphipathic and outline the amphipathic properties of phospholipids.

• Explain why phospholipids form bilayers in water, with reference to hydrophilic phosphate heads and two hydrophobic hydrocarbon tails.

Initial knowledge audit

Membrane structure (vision learning)

Thought experiment

Thought experiment answers

Phospholipid review

1.3.NOS1:  Using models as representations of the real world-there are alternative models of membrane structures 

• Explain what models are and their purposes in science.

• Describe the observations and conclusions drawn by Gorter and Grendel in discovering the structure of cell membranes.

1.3.S2:  Analysis of evidence from electron microscopy that led to the proposal of the Davson-Danielli model.

• Describe the observations and conclusions drawn by Davson and Danielli in discovering the structure of cell membranes.

1.3.S3:  Analysis of the falsification of the Davson-Danielli model that led to the Singer-Nicolson model.

• Describe conclusions about cell membrane structure drawn from freeze-etched electron micrograph images of the cell membrane.

• Describe conclusions about cell membrane structure drawn from cell fusion experiments.

• Describe conclusions about cell membrane structure drawn from improvements in techniques for determining the structure of membrane proteins..

• Compare the Davson-Danielli model of membrane structure with the Singer-Nicolson model.

1.3.NOS2:  Falsification of theories with one theory being superseded by another-evidence falsifies the Davson-Danielli model.

• Describe why the understanding of cell membrane structure has changed over time.

History of membrane models

Development of membrane knowledge:

• 11X17 template

• Cut outs set 1

• Cut outs set 2

• Example of finished template

Review of membrane history

Articles regarding discovery of membrane structure

Gorter and Grendel video clip

Oreo models of membrane structure

Example 1 of Oreo models

Example 2 of Oreo models

Photo of example model

1.3.S1:  Drawing of the fluid mosaic model.

• Draw and label the structure of membranes.  Include:

• Phospholipid bilayer

• Integral proteins shown spanning the membrane

• Peripheral proteins on membrane surface

• Protein channels with a pore

• Glycoproteins with a carbohydrate side chain

• Cholesterol between phospholipids in the hydrophobic region

• An indication of thickness (10nm)

1.3.U3:  Cholesterol is a component of animal cell membranes.

• Identify the structure of cholesterol in molecular diagrams.

• Describe the structural placement of cholesterol within the cell membrane.

Membrane structure notes

Scitable Cell membranes

Alcohol on membranes lab

Salt on membranes lab

(could also do with detergents)

Membrane CFU

1.3.A1:  Cholesterol in mammalian membranes reduces membrane fluidity and permeability to some solutes.

• Outline how temperature affects cell membrane fluidity. 

• Describe the function of cholesterol molecules in the cell membrane.

Bubble play lab

Bubble lab debrief

Bubble lab videos

Video shows cell membrane being ripped and then repairing

1.3.U2:  Membrane proteins are diverse in terms of structure, position in the membranes and function.

• State the primary function of the cell membrane.

• Contrast the structure of integral and peripheral proteins.

• List at least four functions (with example) of membrane bound proteins.

• Contrast the two types of transport proteins:  pumps and channels.

Membrane protein matching

Membrane proteins CFU

Receptor protein “taste” lab

Simplified version of “taste” lab

Taste receptor genetic analysis

• For students

• For teachers

First few minutes of this TED radio hour about smell receptors (idea:  Find group members by smell - give kids cotton balls with a mystery scent - need to find each other by smell and sit together. Connect to cell membrane receptor proteins.)

How a Human Smell Receptor Works Is Finally Revealed | Quanta Magazine

Membrane concept map

• Terms

• Example 1

• Example 2

Unit review slides

Membrane Headbandz game

Kahoot

Final knowledge audit

1-pager summary