Designing Model Membranes
Day 2: Nature of Science and Engineering NSE 3-6
MSTP Region 11 Teacher Center
Today’s Trainers: Tamara Moore and Selcen Guzey
Engineering Design
Goals
1. Teachers will connect engineering
activities across the standards.
2. Teachers will experience an
integrated engineering and life science
lesson
Agenda
Engineering Standards
 Engineering is Elementary (EiE)
 Just Passing Through: Designing Model
Membranes
 Correlating the EiE unit to State
Standards

Connecting to the Standards
What standards were covered in the
“save the penguins” activity?
 How well did this activity address the
engineering standards? Which specific
standards were addressed?

Connecting to the Standards
1. Energy appears in
different forms,
including heat and
electromagnetism.
4.2.3.1.1
4.2.3.1.3
2. Energy can be
transformed
within a system or
transferred to
other systems or
the environment.
6.2.3.2.3
Describe the transfer of
heat energy when a warm
and a cool object are
touching or placed near
each other.
Compare materials that
are conductors and
insulators of heat and/or
electricity.
Describe how heat energy is
transferred in conduction,
convection and radiation.
Connecting to the Standards
2. Engineering design is the
process of identifying
problems, developing
multiple solutions, selecting
the best possible solution,
and building the product.
4.1.2.2.1
4.1.2.2.2
4.1.2.2.3
2. Engineering design is the
process of devising
products, processes and
systems that address a
need, capitalize on an
opportunity, or solve a
specific problem.
6.1.2.2.1
Identify and investigate a design
solution and describe how it was
used to solve an everyday
problem.
Generate ideas and possible
constraints for solving a problem
through engineering design.
Test and evaluate solutions,
considering advantages and
disadvantages of the engineering
solution, and communicate the
results effectively.
Apply and document an
engineering design process that
includes identifying criteria and
constraints, making
representations, testing and
evaluation, and refining the design
as needed to construct a product
or system that solves a problem.
Connecting to the Standards
Nature of
Science &
Engineering
Physical
Science
Earth & Space
Science
•
•
•
•
•
•
•
•
Matter
Motion
Energy
Human
Interactions
Plate Tectonics
Earth Surface
The Universe
Human
Interactions
Life Science
• Structure &
Function
• Interdependence
• Evolution
• Human
Interactions
Pre-Assessment

Complete Pre-test
EiE-Engineering is Elementary
EiE was developed by the Museum of Science
in Boston in 2003. Funded by NSF grant.
 Integrate engineering and technology into
science lessons that you currently teach.
 Does not explicitly teach the science, adds
on to deepen knowledge by combining one
field of engineering with science content.
 The units are not built upon each other; so
they can be taught as a stand alone or in any
order.
 http://www.mos.org/EiE
EiE-Engineering is Elementary
The main goal of EiE:
 Increase children’s technological literacy.
 Increase elementary educators’ abilities to
teach engineering and technology to their
students.
 Modify the educational systems to include
engineering at the elementary level.
 Conduct research and assessment to further
the first three goals and contribute
knowledge about engineering teaching and
learning at the elementary level.
An Overview of EiE Kits for grade 3-5
Unit Title
Science Topic
Engineering
Field
Water, Water Everywhere: Designing water filters
Water
Environmental
Marvelous Machines: Making Work Easier
Simple
Machines
Industrial
Sounds like Fun: Seeing Animal Sounds
Sound
Acoustic
Just Passing through: Designing Model Membranes
Organisms
Bioengineering
An Alarming Idea: Designing Alarm Circuits
Electricity
Electrical
A Stick in the Mud: Evaluating a Landscape
Landforms
Geotechnical
Thinking Inside the Box: Designing a Plant Package
Plants
Package
The Attraction is Obvious: Designing a Maglev System
Magnetism
Transportation
Now You are Cooking: Designing Solar Ovens
Energy
Green
A Long Way Down: Designing Parachutes
Astronomy
Aerospace
Solid as Rock: Replicating an Artifact
Rocks and Minerals
Materials
A Slick Solution: Cleaning an Oil Spill
Ecosystem
Environmental
Taking the Plunge: Designing Submersibles
Sinking and Floating
Ocean
EiE Story Books
Teacher Guide
Each EiE Unit includes:
 Lesson plans
 Duplication Masters (e.g., student
handouts) leveled for Basic and Advanced
abilities.
 Assessment materials
 References for background resources
Teacher Guide Structure
Overview
 Prep Lesson
 Lesson 1: Engineering Story
 Lesson II: A broader view of an
engineering field
 Lesson III: Scientific data inform
engineering design
 Lesson IV: Engineering design challenge
 Assessment

More on EiE
Story books: $6.99
Teacher guides: $45
Materials kits: most around $300
EiE Educator Resources: search for
content connections, multimedia tools,
and supporting documents
Technology in a Bag Activity
In your group, discuss what comes to
mind when you hear the word
“technology.”
 Come and grab your mystery bag!
 Identify a technology in your bag!

◦
◦
◦
◦
What material is it made of?
What problem does it solve?
How else could you use it?
What other materials could it be made of?
Overview of “Just Passing Through:
Designing Model Membranes”
1. Juan Daniel’s Futbol Frog (Prep: 10-15 min., lesson: 90-120 min.)
2. Biology Meets Technology (Prep: 10-25 min., lesson: 45-50 min.)
3. Exploring Membranes (Part I: Prep: 10-15 min., lesson: 45-50 min.,
Part II: Prep: 15-20 min., lesson: 55-60 min.)
4. Designing Model Membrane
(Part I: prep: 10-15 min. lesson: 55-60 min.,
Part II: prep: 10-15 min. lesson: 45-50 min.)
Lesson I:
Story of Juan Daniel’s Futbol Frog
Goals of the Story Book:
 The story presents context for relevant
science content and engineering design
challenge.
 It introduces science and engineering
vocabulary and field of engineering.
Story of Juan Daniel’s Futbol Frog
Read the story and then answer the
following questions individually:
 What part of the story did you like most?
 Why was it important that Juan Daniel
learn about membranes and how they
work?
Share your responses with someone next
to you!
Kristin Peters, the Bioengineer
What does Kristin Peters do?

As a team discuss about bioengineering
and the roles of bioengineers.
Bioengineering
Many bioengineers , instead of creating new devices or
materials, focus on learning just how that living tissue
work. UCSD senior Lisa Serventi (pictured left) works in
a lab studying the fluid that lubricates joints, figuring out
how different molecules in the fluid help to lower
friction.
Engineering Design Cycle

What process did Ms. Peters teach Juan
Daniel about to help him solve his
problem?
Introducing the EDP

Individually complete the “Juan Daniel and
the Engineering Design Process” worksheet.
Lesson II:
Biology Meets Technology
Guiding question: How do bioengineers use natural
objects to inspire human-made technologies?
1) As a team discuss the following questions:
 What technology did Juan Daniel design?
 What inspired his design?
2) Card game time!!!
3) Individually complete the “Technology Match-up
worksheet.”
Membrane

Why is it important for Juan Daniel to
keep his frog’s skin moist?

When Juan Daniel sees the waterfall, what
does he realize about his design?

Why can’t Juan just fill the bowl with
water and leave it covered?
Membrane

As a team define the word “membrane”
and discuss how membranes help
organisms meet their basic needs.
A membrane is a structure that….
Definition

A membrane is a structure that organizes
and maintains cells as separate and
distinct molecular environments.
Membrane
All cells are
surrounded by a
cell membrane!
CellCells are
surrounded by
membranes
TissueCells form
tissue
OrgansTissues form
organs
Organ
SystemsOrgans form
organ systems
OrganismOrgan systems
form
organisms
Membrane
Epithelial tissue covers all external
surfaces, internal cavities, and organs
 What are the functions of epithelial
tissue?

◦ Protection
◦ Absorption
◦ Secretion
Membrane Models

Simple Epithelium vs. Stratified Epithelium
Single layer (frog skin)
Multiple layers
(human skin)
Lesson III: Exploring Membranes
Guiding question: What are some properties
of natural membranes and what materials
might be good choices for designing a
model membrane?
Part I:
 Raisin demonstration
 Egg demonstration
 Iodine-cornstarch demonstration
Lesson III: Exploring Membranes
Raisin Demonstration
Observing:

a)
b)
c)
d)
Dried raisins
Raisins that have been submerged in water for 24
hours
Raisins that have been submerged in a mixture of sand
and water for 24 hours
Raisins that have been submerged in water for 3 hours
Documenting:
Individually complete the “Exploring Membranes: Raisin Skin”
worksheet
Raisin Demonstration
What are your observations of the
soaked raisins?
 Why do the raisins swell when soaked in
water?

◦

Raisin skin acts as a membrane and allows
water to pass through.
How does the water travel across the
raisin membrane?
Membrane Structure

All cell membranes share a common structural
organization:
Bilayers of phospholipids
Hydrophilic head
Hydrophobic tail
The fluid mosaic model by S. J. Singer and G. L. Nicolson
(1972).
Membrane Lipids
Membrane Lipids are the building blocks of the
membrane, they provide the basic structure.
Lipids include fat and cholesterol and do not
dissolve in water.
A phospholipid is a lipid that contains
phosphorus.
The lipid composition of different cell membranes
varies! In addition to the phospolipids, animal
cell membranes contain glycolipids and
cholesterol.
Passive Transport-Diffusion

Diffusion is the process by which
molecules move from an area of higher
concentration to an area of lower
concentration.
Diffusion
Passive Diffusion: A molecule simply
dissolves in the phospholipid bilayer.
Direction to transport is determined by
the concentrations (number of molecules
per unit volume) of the molecule inside
and outside. Ex: gases such as oxygen
More on Raisin Demonstration


What will happen when you put a raisin in
pure water for 48 hours?
What will happen when you put a fresh
grape in salt water?
◦
◦
◦
Membranes have holes that are too small to see!
The high concentration of sugar molecules
inside the raisin creates a concentration
gradient. Water flows inside when the raisin in
placed in water.
Membranes control the rate at which things
pass through
Osmosis with Egg
Step 1: Obtain two eggs and two beakers
Step 2: Pour vinegar into each beaker and add one egg to each beaker
of vinegar - leave them overnight.
Step 3: Remove the eggs and rinse with water and weigh each egg.
Step 4: Pour distilled water into the Egg #1 beaker and pour corn
syrup into the Egg # 2 beaker
Step 5: After 24 hours, observe each egg and measure the mass of
each egg.




What is the purpose of step 2?
What do you think Egg #1 will look like at step 5? Why?
What do you think Egg #2 will look like at step 5? Why?
What will be the relative masses of the eggs at step 5?
Osmosis-The diffusion of the water!

Osmosis is the movement of water across
the membrane.
Although water molecules are polar, they
are small enough to pass the membrane!
http://www.youtube-nocookie.com/watch?v=sdiJtDRJQEc&feature=related
When you put a cell into a solution 3 things can happen:
More water
Fewer dissolved
substances
Less water
More dissolved
substances
The Cell Membrane is
Semipermeable

Only certain molecules can pass through the membrane
since it is semipermeable. Small uncharged molecules can
diffuse freely through lipid barriers. The bilayer is impermeable
to large molecules (e.g., glucose, ions)
Osmosis with Egg
What we have learned:
 An egg is a large single cell surrounded by
membranes that lie just inside the shell.
 The egg membrane behaves the same as
the raisin membrane
◦ An egg in distilled water will gain water by
osmosis (diffusion)
◦ An egg in corn syrup will lose water by
osmosis (diffusion) and thus mass and
circumference!
Lesson III:
Iodine – Cornstarch Demo
What happens when iodine and cornstarch mix?

Iodine plus cornstarch is blue in color
Fill cup 1 with cornstarch and
then fill a baggie with a
mixture of water and a few
drops of iodine. Place the bag
into cup 1 and wait 6 hours.

Fill cup 2 with a mixture of
water and iodine and then fill a
baggie with a mixture of water
and a tablespoon of cornstarch.
Place the bag into cup 2 and
wait 6 hours.
What do you think you will observe after six hours? Explain your
prediction.
More on Membrane Structure
The cell membrane controls materials going into and out of the cell.
Membrane Proteins
Membrane Proteins carry out specific
functions.
Some of the proteins control the
movement of the materials into and out
of the cell.
Membrane Proteins
Facilitated Diffusion: A molecule is carried by carrier or
channel proteins via a concentration gradient. Ex:
carbohydrates, amino acids.
Channel proteins form open pores
Carrier proteins selectively bind the molecules
Transport Across Cell Membranes
Passive Transport: The movement of
particles across a cell membrane without
the use of energy by the cell is called passive
transport.
Active Transport: A process of transporting
particles that requires the cell to use energy
is called active transport.
Active Transport

If molecules are transported in an energetically
unfavorable direction across membranes this process is
called active transport.
http://www.youtube-nocookie.com/watch?v=STzOiRqzzL4&feature=related
Iodine/starch Demonstration
What we have learned:
•Membranes are semi-permeable – they have small holes and
molecules pass through them based on size (and charge).
•The cornstarch cannot pass through the holes in the
dialysis tube since it is a big molecule. Iodine is a small
molecule relative to cornstarch easily pass through the
membrane (dialysis tube)
•Human engineered structures can behave like cell
membranes
Lesson III: Exploring the Membranes
Part II:
 Testing the performance of several model
membrane materials (e.g., coffee filter,
cheese cloth, felt, aluminum foil, etc.)
As a team discuss the following questions:
1.
What materials might be good choices to design a model membrane?
2.
Group materials that can let water pass through at a slow rate. What
properties do these materials have in common?

3.
Group materials that can let water pass through at a fast rate.What
properties do these materials have in common?

As a team test your materials (pour ½ cup of water and
wait 30 seconds to measure how much water has passed)
and complete “The Testing Model Membrane Materials”
worksheet
Lesson IV:
Designing a Model Membrane

What is a model?
◦ A system that explains, describes, or represents
another system
◦ Contains elements, operations, and relations
that allow for logical relationships to emerge
◦ Sometimes not sufficient to completely
describe the system it represents
 If it is a useful model, it closely approximates the
system in a manner that people can use when
working with the system without being unnecessarily
complex
Lesson IV:
Designing a Model Membrane
Guiding question: How can we design a model membrane
based on what we have learned in this unit?
Part I: Planning, making model membranes, and
testing. Use the engineering design cycle!!!
You have been hired by an engineering team to help
Juan Daniel design a model membrane to protect
his lucky frog while he plays fútbol.
1) As a team plan your model membrane!
◦ A successful model membrane design should…
◦ How much water do you think should pass through
your membrane?
2) Test your model!
3) Collect data 24 hours after you complete Part I.
Goal of Design After 24 Hours
Lesson IV:
Designing a Model Membrane
Part II: Checking initial membrane designs,
measuring the water that passes through the
membranes, revising model membranes
We won’t have time to really do this part. If you
want to continue on, consider the following
questions:
 How much water passed through your design?
 Do you think your design was successful? Why
or why not?
 How can you improve your design?
Create
Improve
Test
Implementation Options

After Science unit
Lesson
Time to
Complete
(60 min
sessions)
1. Juan Daniel’s
Futbol Frog
2-3 sessions
2. Biology Meets
Technology
1 session
3. Exploring
Membranes
2 Sessions
(Part 1, 2, )
4: Designing a
Model Membrane
2 Sessions
(Part 1, 2, )

Integrated with FOSS unit
Curriculum
Lesson
FOSS: Structures of Life
Invest. 1: Seeds
FOSS: Structures of Life
Invest. 2: Growing Further
EiE : Just Passing Through
1. Juan Daniel’s Futbol
Frog
EiE : Just Passing Through
2. Biology Meets
Technology
FOSS: Structures of Life
Invest. 3: Meet the
Crayfish
Invest. 4/5: Snail/Beetles
EiE : Just Passing Through
3. Exploring Membranes
EiE : Just Passing Through
4: Designing a Model
Membrane
Water, Water Everywhere:
Designing Water Filters
This unit focuses on water cycle, the
human need for clean and safe drinking
water, and the role of environmental
engineers in providing and maintaining
clear water.
 Lesson 1: Story book
 Lesson II: Environmental engineers
 Lesson III: Exploring filter materials
 Lesson IV: Designing a water filter

New Challenge
Your frog also needs clean water. Thus
your membrane design should also be
able to filter the contaminated water!
 Time to redesign your membrane!

Wrap-Up

What have we learned about membranes?
As a team list five things that you have
learned about the structure of a
membrane and properties of a
membrane.
Misconceptions about Cell
Membranes
Membranes consciously control what
moves through them and what does not.
 Model membranes are exactly the same
as actual membranes.
 If the holes in a membrane are invisible to
the naked eye, nothing can pass through
the membrane.
 Skin is a membrane… in fact, story is
wrong/EiE curriculum is misleading

◦ This is too much of a simplification
Post-Assessment

Complete Post-test
An Overview of EiE Kits for Grade 3-5
Unit Title
Science Topic
Engineering
Field
Water, Water Everywhere: Designing water filters
Water
Environmental
Marvelous Machines: Making Work Easier
Simple
Machines
Industrial
Sounds like Fun: Seeing Animal Sounds
Sound
Acoustic
Just Passing through: Designing Model Membranes
Organisms
Bioengineering
An Alarming Idea: Designing Alarm Circuits
Electricity
Electrical
A Stick in the Mud: Evaluating a Landscape
Landforms
Geotechnical
Thinking Inside the Box: Designing a Plant Package
Plants
Package
The Attraction is Obvious: Designing a Maglev System
Magnetism
Transportation
Now You are Cooking: Designing Solar Ovens
Energy
Green
A Long Way Down: Designing Parachutes
Astronomy
Aerospace
Solid as Rock: Replicating an Artifact
Rocks and Minerals
Materials
A Slick Solution: Cleaning an Oil Spill
Ecosystem
Environmental
Taking the Plunge: Designing Submersibles
Sinking and Floating
Ocean
Correlate to State Standards
Engineering Standards
1
Juan Daniel’s Frog
2
Biology Meets Technology
3
Exploring Membranes
4
Designing a Model
Membrane
Characteristics of Good Engineering
Curricula
Context
 Science/Math Content

◦ (even better if there are other content too)

Scientific Inquiry
◦ Could include design of experiments

Engineering Design
◦ Design cycles
◦ Redesign
Exit Slip
Which of the EiE curricula are you most
interested in implementing? Why?
 On a separate piece of paper, answer the
question above and write one personal
reflection from this training that you
would like to share with the MSTP
Instruction Team.
 Turn this in as you leave.
