HCPSS Curriculum Framework
(using essential components identified by DOI and MSDE structure)
Title: The Transport of Substances Into and Out of Cells.
1. Overview. (This is a brief description of the unit. It explains the unit's focus and/or theme and provides a summary of what students will learn.
This is a scholarly explanation of the highlights of the unit content illuminating the content challenges and connections for teaching the unit.)
The cell membrane acts as a selectively permeable barrier, allowing only certain substances to cross the membrane. Substances can move by
passive transport, or by active transport. The structure of the cell membrane (including the proteins in the membrane) determines what
substances can enter or leave the cell. Movement of substances is driven by concentration gradients ( passive transport) or by cellular energy in
the form of ATP (active transport). Cells need to maintain stable internal conditions in order to carry out normal activities. If the proper
concentrations of salts and water (and other molecules) are not maintained within cells, cell activities will be impaired.
Challenges and Connections: This unit begins with a real-life example of a woman who drank an excessive amount of water in a short time span,
became ill, and died. The purpose of the example is to provide a real-life connection for students. The activities and labs allow the students to
visualize evidence of diffusion and osmosis. The use of simulations allows students to see the behavior of the cell membrane and of the
movement of molecules too small to see with the microscope and helps students to build a deeper understanding of the factors that affect the
transport of substances across membranes.
2. Enduring Understandings. (These go beyond discrete facts or skills to focus on larger concepts, principles, or processes. They are transferable–
applicable to new situations within or beyond the subject.)
● All organisms are made up of at least one cell.
● Like organisms, individual cells maintain homeostasis (i.e., a contstant internal environment).
● The movement of substances into and out of the cell is needed for cells to acquire nutrients and get rid of waste.
● The structure of the cell membrane allows it to regulate what can pass through it (structure determines function).
● Movement of a substance across the cell membrane can occur passively (without input of cellular energy) by moving down its
concentration gradient.
● Active transport processes deliver substances to the inside or outside of the cell, independent of the concentration gradient of the
substance, and require cellular energy in the form of ATP.
● If cells in an organism do not maintain homeostasis, this can cause illness or even death in the organism as a whole.
3. Essential Questions. (What is the walk away knowledge and understanding for students?)
Driving Question: “How can drinking too much water be harmful?”
Sub-questions:
● How do cells control how much water and salt goes in and out?
● What is the cell membrane made of?
● What role do lipids and proteins in the cell membrane play in controling what enters and leaves cells?
● How does the structure of the cell membrane affect its function?
● What are active and passive transport?
● What is diffusion and what drives it?
● What is osmosis and what drives it?
● How do large substances get into and out of cells?
● Why do cells need to maintain stable internal conditions?
● What, if any, are the effects on the organism as a whole if the individal cells do not maintain homeostasis?
4. Interdisciplinary Connections. (This section can broadly list the content areas the unit covers and suggest opportunities for "making
interdisciplinary connections.” This should be both inter and intra connections, for example the disciplines of social studies create intra
connections and inter connections to ELA within almost every lesson.)
Literacy in science –
● Reading to inform
● Using videos and animations in conjuction with text to inform
● Reading and following experimental procedures
● Class discussions to generate and answer questions
● Written responses to lab anaylsis questions and other prompts
Mathematical applications –
● Comparing relative values (weight, concentration)
● Graphing data
● Interpreting graphs
Physics Connections-● Particle movement in diffusion and osmosis
● Kinetic energy of atoms, ions, and molecules
● The effect of temerature on the movement of atoms, ions, and molecules
5. Content Curriculum Map
Curriculum
Standards
MSDE Core Learning
Goals
Expectation 3.1. The
student will be able to
explain the
correlation between
the structure and
function of
biologically important
molecules and their
relationship to cell
processes.
Indicator 3.1.2. The
student will be able to
discuss factors
involved in the
regulation of chemical
activity as part of a
homeostatic
mechanism.
Expectation 3.2. The
student will
Concepts/Topics/Vocabulary
(What will you teach?)
These are concepts and terms that will be
encountered-often for the first time, over the course of
the unit. The list is not comprehensive; it is meant to
highlight terms that either are particular to the unit,
are introduced there, or that play a large role in the
work or content of the unit. These terms and concepts
are usually implied by the standards, but not always
made explicit in them.
● What is water intoxication?
● What is hyponatremia?
● The cell membrane is the outer
boundary of the cell. Its functions are:
● To serve as a flexible yet strong
boundary separating the inside and
outside of the cell;
● To regulate what enters and leaves
the cell.
● The cell membrane is made up of a
phospholipid bilayer studded with
proteins.
● The polar heads of the phospholipids
face the watery outside and cytoplasmic
(inside) faces of the cell while the
nonpolar fatty acid tails are embedded in
the middle of the bilyar.
● Since the membrane is mostly lipid,
substances that are not lipid soluble (or
hydrophobic) cannot readily cross the
membrane.
● Some proteins project to the outside of
Student
Outcomes
(What will students do?)
Students will:
● Be introduced to
the case of
Jennifer Strange
who drank a
large amount of
water in a short
period of time.
● Identify and
discuss key ideas
and potential
connections to
what science
students already
know.
● Identify what
concepts they
need to know
more about in
order to
understand the
reasons why
Skills/Engagement
Assessment
(How will you teach it and how will you
engage students?)
(How will students show you what
they know?) These are formative
(pre and on-going) and summative
(graded post/unit assignments)
assessment
● View video clip, “Woman dies
after water-drinking contest”.
● Read article, “Strange but True:
Drinking Too Much Water can
Kill”.
● Make a KWL chart based on the
article (refer back to this
frequently throughout unit) to
connect to the Driving
Question.
● Bubble Membrane Lab
● “Construction of the Cell
Membrane” online tutorial
● “Build a Cell Membrane” paper
model (3D or 2D)
● Think-Pair-Share: “Based on
what you have learned so far,
can you predict what
substances will pass through
the cell membrane?”
● Candle/air freshener teacher
demonstration of diffusion.
● Pre
● Teacher-created Preassessment
● KWL
● Candle/Air freshener
demonstration
Predict-ObserveExplain (POE)
responses
● Food coloring
demonstration (POE)
responses
● Ongoing
● Bubble Membrane Lab
responses
● Construction of the
Cell Membrane online
tutorial responses
● Build a Membrane
(paper model) and
identify the parts
demonstrate an
understanding that all
organisms are
composed of cells
which can function
independently or as
part of multicellular
organisms.
Indicator 3.2.1. The
student will explain
processes and the
function of related
structures found in
unicellular and
multicellular
organisms.
Indicator 3.2.2. The
student will conclude
that cells exist within
a narrow range of
environmental
conditions and
changes to that
environment, either
naturally occurring or
induced, may cause
changes in the
metabolic activity of
the cell or organism.
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the membrane, others project to the
cytoplasmic face of the membrane, and
others traverse the entire membrane.
The proteins have different functions,
such as cell-cell recognition, signaling,
receptors for hormones, and more.
Some proteins in the membrane act as
channels, containing tiny openings
(pores) that allow substances to cross the
membrane.
Some channel proteins help transport
substances across the membrane and are
called tranport proteins.
The structure of the cell membrane
serves to regulate what may cross it.
Since not all substances can cross, it is
known as a semi-permeable membrane.
Substances can move across the
membrane by passive transport, or by
active transport.
The 3 processes of passive transport are:
(1) simple diffusion; (2) osmosis; and (3)
facilitated diffusion.
In each case, the solute moves from an
area of higher concentration to an area
of lower concentration.
Diffusion is driven by the random
movement of atoms or molecules due to
their intrinsic kinetic energy.
Osmosis refers specifically to the
diffusion of water across a semipermeable membrane.
Jennifer’s body
could not cope
with drinking a
large amount of
water.
● Describe
characteristics of
the cell
membrane
based on a
simulated model
(Bubble
Membrane).
● Describe the
structure of the
cell membrane.
● Explain how the
structure of the
celll membrane
relates to its
functions.
● Explain the
processes of
diffusion and
osmosis.
● Predict whether
a substance will
be able to cross
the cell
membrane.
● Predict the
direction of
Predict-Observe-Explain (POE).
Will everyone smell the scent at
the same time? Why or why
not?
● Diffusion of food coloring in
water (use hot, cold, & room
temp. water) student lab or
teacher demonstration; POE.
Why did the food coloring
distribute fastest in the hot
water? Slowest in cold?
● Diffusion Lab (dialysis tubing,
starch, iodine).
● Osmosis Lab (Part 1: potato;
Part 2: Elodea, using
microscope).
● Molecular Workbench online
simulation of diffusion and
osmosis.
● Osmosis practice problems
(printed or interactive online):
predict what will happen to cells
placed in various solutions
(hypertonic, isotonic,
hypotonic).
● Think-Pair-Share/class
discussion: What might be a
situation where the cells in
your body need to move
substances out? In? (Some
examples are that cells in the
stomach pump H+ ions into the
● Think-Pair-Share
responses
● Student written
response to lab
questions and
graphing
● Student written
responses to online
Diffusion & Osmosis
simulation questions
● Osmosis practice
problems
● Quick write: How are
diffusion and
facilitated diffusions
similar and different?
● Quick write: How are
facilitated diffusion
and ion pumping
similar and different?
● POE responses to “Just
Passing Through”
● Skier analogy quick
write: When a skier
goes down a hill, what
type of transport is
that most similar to?
Up a hill?
● Student solution to
Jelly Bean problem lab
● Name some examples
of cells using
● In a hypertonic solution the
concentration of solutes in the
extracellular fluid is higher than inside
the cell.
● In a hypotonic solution, the
concentration of solutes in the
extracellular fluid is lower than inside the
cell.
● In an isotonic solution, the concentration
of solutes in the extracellular fluid is the
same as inside the cell.
● In facilitated diffusion, a transport
protein assists in the passive transport of
larger molecules.
● The three types of active transport are
(1) ion pumping; (2) endocytosis; and (3)
exocytosis.
● Active transport processes require input
of cellular energy in the form of ATP.
● In active transport of ions, the solute
moves from an area of lower
concentration to an area of higher
concentration.
● Endocytosis and exocytosis (also known
as bulk transport processes) involve the
bulk movement of large particles or
molecules either into or out of the cell,
respectively.
● Two common types of endocytosis are:
(1) phagocytosis, where large particles
(such as bacteria) are taken into the cell;
and pinocytosis, where liquids are taken
movement of
ions, molecules,
and water across
cell membranes.
● Describe the
processes of
passive and
active tranport
and explain the
similarities and
differences.
stomach lumen to produce acid
for digestion; water moves out
of cells after eating a salty
meal; glucose moves into cells
after eating; water moves into
cells after drinking a lot of
water).
● Show animations of facillitated
transport and sodiumpotassium pump. What are the
similarities and differences?
● Show cell membrane animation
“Just Passing Through.” Student
POE how molecules will move
and in what direction. Why are
all the molecules wiggling?
● The Jelly Bean problem activity.
● Show animations and video clip
of endocytosis and exocytosis.
endocytosis and
exocytosis
● Summative
● Teacher-created Postassessment
● Public release HSA
questions
● County Assessement
● Writing prompt: How
are the changes
observed in the Elodea
cells (Osmosis lab)
similar to what
happened to the cells
in Jennifer Strange
after drinking too
much water? Include
relevant vocabulary
and evidence from
your observations in
your response.
● Writing prompt:
Explain how drinking
too much water in a
short amount of time
can cause changes at
the cellular level
resulting in serious
illness or death. Use
what you have learned
into the cell.
in this unit to support
your answer.
6. Lesson Plans/Seeds. (The lesson seeds are ideas that can be used to build a lesson. They are designed to generate evidence of student
understanding and give teachers ideas for developing their own activities. Lesson seeds are not meant to be all-inclusive, nor are they substitutes
for instruction.)
● “Strange but True: Drinking Too Much Water can Kill” article, video, and KWL
● Bubble Membrane lab
● Build a Cell Membrane (online tutorial and paper model)
● Candle/air freshener teacher demonstration of diffusion and diffusion of food coloring in water (use hot, cold, & room temp. water)
student lab or teacher demonstration
● Diffusion Lab
● Osmosis Lab
● Online simulation of diffusion and osmosis
● Animations and videos of active transport
7. How will you teach the content or how will students learn the content independently? (Multiple Means of Representation)
● Visual Learners
● Class KWL chart
● Bubble simulation of the cell membrane lab
● Build a Membrane online (has animations)
● Build a Membrane (paper)
● Visualizing evidence of diffusion and osmosis through demonstrations and labs
● Create a cartoon video explaining passive or active transport http://www.toondoo.com/
● Create an animated movie explaining passive or active tranport http://www.xtranormal.com/ or
http://www.samanimation.com/
●
Kinesthetic Learners
● Build a Cell Membrane (online)
● Build a Cell Membrane (paper)
● Bubble Membrane Lab
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Diffusion Lab
Osmosis Lab
The Jelly Bean Problem Lab
Auditory Learners
● Videos with narration
● Online tutorial (Build a Membrane) with narration
● Class discussions
● Create a song or rap explaining passive or active transport http://www.incredibox.com/en/#/application
● Create a voki news reporter explaining passive or active transport http://www.voki.com/
8. How will students be engaged in the content? (Multiple Means of Engagement)
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Videos
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Opening article that highlights a real-life individual’s experience
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Teacher demonstrations
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Student labs and hands-on activities
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Online tutorials, simulations, and interactive practice
9. How will students show you what they know? (Multiple Means of Action and Expression)
● Class discussions and individual sharing prompted by KWL, POE, Think-Pair-Share, labs, and reading
● Written responses to prompts in discussions, POE, and lab analysis questions
● Building and labeling paper models
● Written responses to prompts (quick-writes and defending an inference based on evidence)
● Student responses to online tutorial questions, online simulation questions, and interactive osmosis questions
● Written tabulation and graphing of data
● Web 2.0 Tools
● County assessment
● Teacher and practice HSA test questions
10. Resources. (Substantial lists of suggested literary and/or informational texts and other supporting resources.)
A. Suggested Texts (Literary and/or informational):
● “Strange but True: Drinking Too Much Water can Kill”, Scientific American, June 21, 2007.
http://www.scientificamerican.com/article.cfm?id=strange-but-true-drinking-too-much-water-can-kill
● Biology (McDougal Littell, 2008), pp. 81-91
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Holt Biology (2009), pp. 77-78 and 97-107
Miller & Levine Biology (2006), pp. 203-213
B. Suggested Media to support this unit:
● “Woman dies after water-drinking contest”, NBC News, 1/13/07.
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http://www.msnbc.msn.com/id/16614865/ns/us_news-life/t/woman-dies-after-water-drinking-contest/
How Diffusion Works (McGraw-Hill): http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html
How Osmosis Works (McGraw-Hill): http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html
How Facilitated Diffusion Works (McGraw-Hill): http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html
How the Sodium-Potassium Pump works: http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html
“Just Passing through” Membrane Animation: http://www.teachersdomain.org/asset/tdc02_int_membraneweb/
Endocytosis/exocytosis video: http://www.dnatube.com/video/1591/Cell-Membrane-Exocitosis--Endocitosis
Phagocytosis videos: http://www.dnatube.com/video/102/Phagocytosis
http://www.dnatube.com/video/7271/Amoeba-Phagocytosis
http://www.dnatube.com/video/1040/Fagositosis
C. Technology resources:
● “Construction of the Cell Membrane” online activity and tutorial: http://www.wisc-
online.com/Objects/ViewObject.aspx?ID=ap1101
Molecular Workbench online simulations in Diffusion and Osmosis (select “Diffusion” at the web page):
http://mw.concord.org/modeler/
● Osmosis practice (interactive): http://arbl.cvmbs.colostate.edu/hbooks/cmb/cells/pmemb/osmosis_eg.html
D. Labs:
● Bubblicious Membrane Lab: http://www.myteacherpages.com/webpages/tkeilman/files/bubblelicious%20membrane1.doc
● How to make bubble solution: http://www.exploratorium.edu/ronh/bubbles/formulae.html
● Diffusion Lab: http://serendip.brynmawr.edu/sci_edu/waldron/pdf/MembraneProtocol.pdf
● Osmosis Lab: http://www.utsouthwestern.edu/media/other-activities/251270osmodemo.pdf
● The Jelly Bean Problem (endocytosis) http://www.accessexcellence.org/AE/AEC/AEF/1996/westover_jellybean.php
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A. Other Resources:
● Build a membrane paper model (3D): http://teach.genetics.utah.edu/content/begin/cells/print/BuildAMembrane.pdf
● Paper membrane model (2D):
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http://classroom.westsidehsfaculty.org/webs/dwalters/upload/10_the_fluid_mosaic_membrane.pdf
Osmosis practice (to print): http://washington.spps.org/uploads/More_Osmosis_Practice_Problems_HMWK.pdf