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Teacher Guide for Amplify Cell Structure and Function Module

SESSION 1

The guide provides you with extra support for teaching certain key topics in Session 1.

Key goals for Session 1

• Discuss the context for why we should learn about cells

• Develop questions that will drive student investigations throughout the module

• Engage students in the investigation

• Get students comfortable with the simulation

We recommend that Session 1 (including the pre-assessment) be taught over two days (a total

of approximately 1.5 hours of class time).

Warm-up

• Quick student refresher on cell theory

Students will benefit from prior exposure to cell theory. This warm-up provides an

opportunity to review some cell theory, including (i) what makes something living or non-

living; (ii) that cells are the basic unit of life and that everything is made of cells; and (iii)

various misconceptions.

Introduction to Cells

• Develop driving questions

Lead a discussion with students to develop driving questions that will guide their subsequent

investigations in the module. Allow students to brainstorm as much as possible and guide

the conversation. Ultimately the goal is to develop overarching driving questions about the

connection between the organism and the cell, including such possibilities as:


» Why does the health of our body rely on the health of our cells?

» Why do we need to eat and breathe?

» What happens in our cells when the body is sick?

» Why does our body get sick when our cells can’t fulfill their functions?

Emphasizing the connection between the cell and the organism drives student engagement

in the module and reminds students that they are studying the cell in service of

understanding the organism.

• Why do we eat and breathe?

Once the class has a general overarching question (or several) about the cell’s connection to

the body, let students know that they’re going to start exploring this connection by focusing

on why we need to eat and breathe.

Begin by asking students why they think humans need to eat and breathe. Students often

respond with something like “the body needs nutrients from food” or “the body needs

oxygen.” Probe students with questions like “What do you mean by the body?” or, “What in

the body needs oxygen and nutrients?”

Students then tend to identify organs like the lungs or the stomach. Push further, asking

questions like “Why do organs need oxygen and nutrients, which come in the form of

molecules?” to guide them to tissue. Eventually, students will suggest the connection

between eating and breathing and cells.

» You might want to push even further: “Well, why do cells need oxygen and sugar? How

do they use them? And what are they?” This is a good opportunity to introduce students

to molecules and organelles.

» Repeat this process for both eating and breathing

» This conversation allows students to explore the concept of scale, and puzzle out

important connections. Capture and group students’ ideas on the board (organism >

organ > tissue > cell > organelle > molecule) to facilitate their mastery of scale.

Video

• Get students thinking about cells

As students watch the video, you may want to point out when the video transitions from

outside of the cell to inside of the cell. It is also helpful to note that all of the activity they are

observing in the video is happening inside of their cells right now.

Note: You will return to the video in Session 2 after students know more about the cell system.


• Discussion

After the video concludes, invite students to point out anything from the video that they

found new, interesting, or surprising. As they share, emphasize the cell system and begin

pointing out the organelles and their functions. The purpose of the video and this discussion

is mostly engagement and setting the stage; they will discover much more about these

organelles in the next session.

Simulation Tutorial

• What is a simulation?

Discuss that a simulation is a way for us (and scientists) to investigate complex systems that

are not easy to examine directly. Let students know that simulations are one way to represent

the cell system. Although simulations are extremely helpful for studying complex systems,

the rules underlying the simulation – the model – are always going to be simplifications in the

case of something as complicated as the cell system.

• Introduce the tutorial/simulation

Let students explore the simulation on their own for a few minutes before checking in to see if

they understand what they are seeing. At this point you want students to understand:

» The simulation shows a cutaway of a single cell

» The cell is surrounded by other cells that are not “cut away” (this is why they look

different and we can’t see inside of them)

» At the top of the screen is a blood vessel (its walls are made of other cells) which carries

blood with nutrients and red blood cells

• Exploration/Tutorial

The goals of the tutorial are to familiarize students with the features of the simulation:

» Trace molecules

» Control molecules

» Hide/show molecules

» Turn organelles off/on

You may want to start discussing the purpose of these simulation features. For example, why

is it useful to turn an organelle off or why is it helpful to trace or control a molecule?


Exploring the Cell

• Introducing organelles and molecules

Using the simulation, show and emphasize the difference between an organelle and

a molecule. Consider noting that the objects they see in the simulation are another

representation of the organelles and molecules they saw in the video.

• Vesicles

Let students know that a vesicle is an organelle that carries proteins around and out of

the cell (in the simulation, you can see the protein inside the vesicle) and not a molecule.

Students often assume that vesicles are molecules not organelles, and fail to notice that they

are carrying proteins. This should also help students in Session 2, when they think about

outputs of the cell system. Note that vesicles coming out of the endoplasmic reticulum are

green and vesicles coming out of the Golgi apparatus are purple but both carry protein.

• Focusing on certain organelles

Once students have completed their inventory of molecules and organelles, tell students

that while the cell has a number of organelles (and perhaps they know of some like the

lysosome or Golgi apparatus), they will focus on the mitochondria, nucleus, ribosome, and

cell membrane during this module.

Note: The module focuses on these organelles because they tell the story of energy

transformation and protein synthesis, and because the NGSS specifically calls for students to

learn about the mitochondria, nucleus, and cell membrane.

Scale

• Organism’s connection to the cell

This is an opportunity to remind students that cells are connected to the organism via a

series of intermediate systems—organs, tissue, etc. Mastering the scale relationships is an

important foundation for the rest of the module.



SESSION 2

This guide provides you with extra support for teaching certain key topics in Session 2.


• Reinforce the concept of a system

• Investigate the cell system using the simulation

• Develop and draw a model of the animal cell system

• Understand the basic functions of the mitochondria, ribosomes, the nucleus,

and cell membrane

We recommend that Session 2 be taught over two days (a total of approximately 1.5 hours of

class time). Students generally need two class sessions to complete their investigation of the

animal cell system, develop their model, and then draw it.

Day 1

Investigating the Cell System

• Frame vocabulary

Begin a discussion by asking students “What is a system?” Ask students to suggest a

familiar one—perhaps they’ll suggest a school or a city—and then discuss how a system

works, how different parts have distinct functions that keep everything working, and how

these parts are often interdependent. Remind students that they are investigating the cell

system in service of the larger goal: Understanding the connection between the organism

and the cell and, in particular, learning why humans need to eat and breathe.

• How to investigate the cell system

Ask students how they might use the simulation to investigate the cell. This is an


opportunity for them to strategize about how to conduct an investigation. You may need to

remind them about the functions of the simulation, and the relationship between organelles

and molecules.

• Conducting the investigation

Allow students to conduct their own investigation. If they need help, use guiding questions

to help students make observations: How do this molecule and this organelle interact? Is

the molecule bouncing off of the organelle (no interaction)? Is the molecule going into the

organelle (input)? Is the molecule coming out of the organelle (output)?

» Simulation Tip: Students can focus on one organelle at a time by zooming in on the

organelle. They can focus on one molecule at a time by hiding all but one molecule.

» Simulation Tip: Students can use the molecule panel to hide and show particular

molecules; this is a way to reduce the noise in the simulation and allow students

to study a particular molecule (students will sometimes forget that they’ve hidden

molecules, so you may have to remind them to Show them again).

» Simulation Tip: Students can slow the speed to make observations easier and see

things that are happening very fast. Or they can speed up the simulation to observe

events that happen less often.

» Simulation Tip: Students can use the Control function of the molecules to double-

check their input observations. If they can drive the molecule into the organelle, it

means that the molecule is an input for that organelle.

» Simulation Tip: Students can use the reset function to start over.

» Simulation Tip: Some students may attempt to make observations by turning

organelles on and off. While this is a valid strategy to make observations in the cell,

it can lead to erroneous input/output observations as the cell does not function

normally while organelles are turned off. Explain to students why it is important that

all organelles be functioning correctly to make these observations.

• Reviewing students’ worksheets

After students have completed their Investigation of Organelles worksheet, project this

worksheet and conduct a class discussion about it. Point out that it shows parts of the cell

system and is the basis for a more comprehensive model. You might want to read the first row

(the input/output map for the mitochondria) for your students, encouraging students to follow

along on their worksheets as you read: “Oxygen and glucose (sugar) go into the mitochondria

which produces ATP (energy) and carbon dioxide.” See if anyone found anything different in the

simulation. If so, you can project the simulation and address the misconception.


Ask for volunteers to read the nucleus and ribosome diagrams, reminding students again to

follow along and share any differences. These are good opportunities to reinforce the language

of “inputs” and “outputs,” which are written on the arrows. This process is key to solidifying

their conceptual models.

• Discussing the interconnectedness of the cell system

This a crucial step as students develop their conceptual models: Show how the cell is a

connected system (that is, the outputs of one organelle are the inputs of another). Without

this understanding, students’ drawings of their models often appear disconnected; they will

draw each organelle with its inputs and outputs separately rather than connecting them as

an integrated system. Accordingly, we recommend not skipping this step.

Suggested Procedure:

» Point out that the organelle diagrams on the worksheet may look disconnected,

but there are connections that make this a system. Ask students if they see any

connections.

» Students should note that (i) ATP (energy), which is produced by the mitochondria,

is used as an input by both the nucleus and the ribosomes and (ii) mRNA, which is

produced by the nucleus, is used by the ribosome.

» Ask students how to map these relationships on their worksheets. Students will

generally suggest using an arrow; allowing them to work through how to represent

ideas visually will help develop their modeling skills. Have a student demonstrate

connecting ATP from the mitochondria to ATP going into the nucleus and ribosome.

Have a second student come up and repeat for mRNA.

» Explain to students that these arrows show the relationship between the molecules

and organelles: The mitochondria produces ATP which is needed by the nucleus

and ribosomes. Note that the arrows also indicate the direction of the relationship:

the ATP molecules go from the mitochondria to the nucleus and ribosomes, not the

other way around.

» You can project the Investigation of Organelles Worksheet - Complete with

Connections image to go over the full system with connections.

• Discussing organelle function in the cell system

As students focus on the role of ATP and mRNA in the cell system, you have a great

opportunity to discuss organelle function. You want to ensure that students understand

why the cell system is connected, and not just view it as a puzzle to solve. You can ask


students what they think ATP is doing for the cell. They will often find the role of ATP

fairly intuitive. You can add that the mitochondria is often considered the “power house”

of the cell because it produces ATP. As for mRNA, they may struggle a bit more with the

concept of “instructions.” Point out that the nucleus creates mRNA from DNA, and that the

ribosomes use these mRNA instructions to make particular proteins.

• A note on cellular respiration

In Cell Simulator, students are presented with a simplified view of cellular respiration so

that they can directly observe the function of the mitochondria. Accordingly, glycolysis (the

breakdown of glucose into pyruvic acid) is not represented. Cell Simulator shows glucose

entering the mitochondria to represent the overall cellular respiration process.

Discussing the Cell System

• How is the cell system connected to the body?

This is a crucial teacher-led discussion that connects the cell system they have just

investigated to the world outside the cell (via the cell membrane). In particular, students

should try to figure out the following:

» What does the cell need to obtain from outside the cell? ª Glucose and oxygen enter

the cell via the membrane.

» What does the cell send outside the cell? ªCarbon dioxide and proteins leave the

cell via the membrane.

» What is the role of the cell membrane?

Suggested Procedure:

» Remind students they have been focusing on the system inside the cell. Ask them

to extend their model to molecules outside the cell. Students will have noticed that

some molecules enter and leave the cell. Explain the connection between the cell

and the body as a whole: It makes sense that molecules enter and leave the cell

because the cell must take in some molecules from the body and produce some

molecules for the body. Also note that some molecules stay within the cell.

» Project the cellular input/output image on the board and fill it out during the

discussion. (Afterward, students will complete the same worksheet in the platform

as a concept check.)

» Ask students to think about which two molecules enter the cell. They should be


able to use their knowledge from prior sessions to answer the question. Remind

them that eating and breathing provides glucose and oxygen—this is one of the key

connections between the organism and the cell.

» Then ask students to think about cellular outputs. Just like humans breathe in

oxygen and breathe out carbon dioxide, the cell releases carbon dioxide as well.

Understanding that proteins leave the cell will not be as intuitive for students,

but they will likely remember this from the simulation. Remind students of the

importance of proteins for all cells in the body and the body as whole. Make a point

of explaining that there are many different types of proteins with many different

roles in our cells and bodies. Should the misconception arise, this is a good

opportunity to note that proteins do not only come from food; many proteins that

the organism needs are produced by cells.

» Finally, ask students how these molecules enter and leave the cell. Which organelle

allows them to do this? Have a discussion about the cell membrane and how it

functions. Students should understand that:

• The cell membrane is semi-permeable and what semi-permeable means.

• Some molecules that are needed by the cell enter through a protein channel.

Note on diffusion: In the simulation, oxygen and carbon dioxide diffuse in and out of the cell

(as in actual cells). This presents an opportunity to talk about diffusion, but students require

a significant amount of time to fully understand the concept. Be sure to let the students know

that bi-directional diffusion is happening in the simulation—their observations are correct— but

that the inputs/outputs the class has recorded indicate the direction in which the majority of

molecules move.

Note on transport channels: It is crucial for Session 4 that students have a basic understanding

of the role and function of the cell membrane, and, in particular, know that certain molecules

need transport channels to enter. This is not intuitive to students. You may want to encourage

students to turn off the cell membrane in the simulation, and then discuss what happens to

reinforce this point.


Day 2

Drawing Your Model

Note: We recommend that students not have the simulation open while drawing; otherwise,

they tend to draw what they see in the simulation rather than following your tips on how to

draw a good representation of a model. Remind students to reference their “Investigation of

Organelles Worksheet” when drawing their model.

• What is a model?

Have a conversation with your students about the scientific practice of modeling. Emphasize

that a model is a conceptual (usually simplified) map of how a system works. The drawing is not

the model itself, but a representation of that model.

• What makes a good representation of a model?

It may be helpful to ask students to imagine that their drawings are intended to explain the

cell system to someone who hasn’t learned about the cell. Some things to note: Drawings

should be simple, easy to read, connected, and use arrows. You can discuss what kinds

of choices are significant. For example, does color, size, or use of images matter? This

discussion is critical, as students otherwise tend to:

» Draw what they see in the simulation very literally with multiple organelles and

molecules with considerable detail; remind students that the simulation is also just a

representation of a model, like the drawings.

» Leave arrows unconnected

» Forget to label the organelles and molecules

• Student drawings

After students have had a period of time to draw, it is often helpful to have them revise another

model. Remind students that they are not simply correcting someone else’s model, they are

collaborating and helping to improve it.

Students’ drawings might end up looking different—but it should be clear that the system

they (and the simulation) describe is the same. If time permits, you can have a discussion

about visual differences between the drawings, while pointing out that the underlying model

is all the same.

If possible, leave students’ drawings up around the room to create an atmosphere of scientific

inquiry and so they can use them during the remainder of the module.



SESSION 3



• Investigate choking and starving as a way to solidify understanding the cell system

and its relationship to the entire organism

• Develop a sense for how glitches in the cell can lead to death of the cell — or even

the organism

The Cell and the Organism

After a deep dive into the cell in Session 2, this is an opportunity to remind students of the

original driving questions — they’re studying cells to better understand the organism as a

whole.

Choking and Starving

• Navigating the simulation — Choking and starving scenarios

To simulate choking and starving in the cell, students should click the + button in the

lower left hand corner of the simulation, and then select Choke or Starve. In the choking

scenario, the concentration of oxygen will begin dropping. In the starving scenario, the

concentration of glucose will begin dropping. Over the following 30 seconds, organelles will

stop working (and change color to indicate that the are not working) and the concentration

of their outputs will drop. At this point, students should be checking to see if their

prediction about which organelles will stop working is correct or not, rather than looking at

the graph — they will return to this later. After the organism has been choking or starving

for a period of time, students can have the organism breathe or eat to return the organism

to health and more vividly demonstrate the effects of the scenarios.


• Function of the organelles

When students compare observations, you can reinforce the function of the cells and the

molecules. Students may point out that the cell dies when the organism is choking or starving

because ATP is not produced. This is a good moment to explain the role of the mitochondria

and ATP in the cell system.

» Emphasize that ATP is energy, so it makes sense that everything stops working

when there’s no energy — much as a city would shut down if there was no electricity.

• Real-life time scales

Some students might ask about the fact that, in real life, starving takes a lot longer (weeks)

while choking is very fast (minutes). While the differences between both processes in real

life are very complex, a simple answer is that the body has the ability to store glucose (as

fat) and use it when it needs to, while it cannot store oxygen. The simulation uses a model

that does not take this into account in order to show how both work more easily.

Graph Tutorial

• Molecular concentrations start changing at different points in time

When you discuss the last graph in the graphing tutorial, if you feel like your class is

prepared for a more advanced discussion of graphing and systems, talk to your students

about why all molecular concentrations don’t drop at the same time. This will get them

thinking about how to graph the cell system more precisely. See Session 3 Differentiation—

Effects Over Time.

Graphing as Evidence

• Identifying which molecules to graph

When discussing how to represent the cell dying in a graph, you may want to make a list of

the affected molecules on the board. If you want to give your students more of a challenge,

you can discuss some of the molecules they would want to include in their graph, but let

them figure out the rest on their own. When pairs of students compare their graphs they

will most likely have graphed different molecules. This leads to a more fruitful conversation

about graphing the cell system and also makes translating their ideas into a master graph

less repetitive.


• Why the amount of some molecules increases

Students may realize that in each scenario, the concentration of one molecule is increasing

(glucose if the organism is choking, oxygen if the organism is starving). Talk them through

why: If the mitochondria lose access to one of these molecules, they can’t function, so the

other molecule that is an input to the mitochondria goes unused and naturally builds up inside

the cell. Remind students that this graph represents a small point in time and that eventually

the cell will shut down completely.

• The order in which molecular concentrations change

When students compare their graphs to the simulation graph, you may want to note that

the amount of various molecules change at different times because they are connected (i.e.

mRNA should start decreasing after ATP decreases).



SESSION 4



• Use the case study of diabetes to further explore the connection between health of cells

and health of the body

• Plan and conduct a detailed scientific investigation

• Begin to develop skill in scientific argumentation

Session 4 is a great opportunity for students to conduct an engaging investigation and learn

about scientific argumentation. It is also the most challenging session in the module. Students

must bring all they’ve learned so far to successfully complete the session. Although it is

tempting to make the investigation a bit easier for students by telling them the answers, try to

take the time needed to guide the students to conduct their own investigation and allow them

to be wrong at times.

We recommend that Session 4 be taught over two days (for a total of approximately 1.5 hours

of class time).


Background

• Falsification of alternative hypotheses

Perhaps the most challenging aspect of this activity is that students need to grapple with

two alternative hypotheses for how insulin might work within the cell. Though scientists now

know how insulin works on cells (see the section on insulin in the Appendix), in this activity

we enable students to walk in the shoes of the scientists who made this discovery. Explain

to students that we will be adding a new molecule to our model for cell function: the protein

insulin. Be sure not to give away the answer!

Students will investigate two working hypotheses for how this new input works:

1. Insulin is an input for the cell membrane and

2. Insulin is an input for the mitochondria

If Hypothesis 1 (the membrane hypothesis) is true, then when insulin is removed, the cell

membrane won’t be able to function normally with respect to glucose. If glucose can no

longer cross the cell membrane, then we’d expect glucose levels inside the cell to decline.

Alternatively, if Hypothesis 2 (the mitochondria hypothesis) is true, then when insulin is

removed, the mitochondria won’t be able to function normally with respect to glucose. If

glucose can no longer be processed by the mitochondria, then we’d expect glucose levels

inside the cell to increase.

Thus, we have two alternative hypotheses, each with an associated prediction about how

glucose levels inside the cell would change without insulin. During the course of this activity,

students will develop a sense of what a scientific investigation entails, grapple with a real

scientific problem, learn to argue with each other in a productive way, and feel the reward

of scientific discovery. And they can use Cell Simulator to facilitate their investigation and

check answers.

• Signposts

Because this is a long and, at times, complicated investigation, always keep students aware of

where they’re headed by providing signposts ahead of time:

» First, we’re exploring the cell to hypothesize how insulin could work.

» Second, we’re setting up an investigation.

» Third, we’ll conduct the investigation and analyze the results.


Day 1

Warm-up

• What do we know about diabetes?

As students may know people with diabetes, this is a chance to get students talking in

a lively discussion before getting into the scientific details. Throughout the discussion,

sift through their comments and highlight, and write on the board, the essential pieces

of information they need to know. This is also a good chance to take note of any student

misconceptions and specifically address those throughout the activities.

• What to do if a student suggests that insulin acts on the cell membrane

If a student volunteers that insulin acts on the cell membrane, either from prior knowledge

or because they observed the transport channels closing in the simulator, we recommend

that you acknowledge the observation as a possibility but remind students that we’re going to

reconstruct the process that the scientists went through in order to confirm the answer.

Introduction to Diabetes

• Video

The key takeaway from this video is the relationship between insulin and glucose. Note that

the video states that insulin is a protein. If you overemphasize this point, students are more

likely to guess that insulin works with the ribosome (since they now know that the ribosome

is responsible for producing proteins).

Exploring Insulin in the Cell

• A good scientific argument

This section incorporates times for students to share their hypotheses with partners and,

eventually, the whole class. This is a good opportunity to discuss what it means to make a

good scientific argument. The goal is to convince others of your hypothesis based on the

power of your argument. We have students select their hypotheses twice in case they have

been successfully convinced by someone else! Oftentimes, students will be convinced by

someone who proposes the “wrong” hypothesis — this is okay and part of the process.

Time permitting, at the end of the activity you may ask students to reflect back on this

moment.


• Historical context

After you’ve helped students narrow their guess to the cell membrane and mitochondria,

remind them that this was an actual scientific debate. This is a good place for some bonus

reading, or extra activity for anyone who wants to explore the history of diabetes research.

• How does a molecule “act on” an organelle?

We’ve found that students struggle with what it means that insulin “acts on” something—but

students need a solid understanding of this concept (and what happens when an input stops

working) for the activity to be successful.

Brainstorm with them about what “acting on” could mean. It may resonate with them to think

of insulin as another input (a concept they’ve already become very familiar with). If insulin

acts on or is an input to the cell membrane, then it helps the cell membrane do its job, which

is letting things in and out. If it acts on the mitochondria, then it helps the mitochondria

do their job, which is taking in glucose and oxygen and producing ATP and carbon dioxide.

Conversely, it is important for students to understand what happens when an organelle

stops working–remind them that a broken cell membrane stops letting in glucose and that a

broken mitochondrion stops producing ATP and CO2. See Session 3 Differentiation—Using the

Simulator to Develop Predictions.

• Working with each other, not against each other

Once separated into groups, students often view themselves as being part of a “team” that

is competing for the correct answer with the other group. Before separating students into

groups, remind them that everyone is working on a different aspect of the same investigation

to figure out how insulin works in the cell.

Research Groups

• Framing the investigation

The most challenging concept for students to understand is what happens if a given organelle

needs insulin to work but insulin isn’t present. Work closely with your students to meet

them at the right level and to make sure they understand what would happen to an insulin-

dependent organelle if there is no insulin.

One option is to refer students back to the input/output worksheet: You can create a

new version of the diagram (on the whiteboard) which adds insulin as a third input for the

mitochondria and the cell membrane. Ask students what would happen in this new diagram

if insulin stopped (the organelle would stop functioning and glucose concentrations would


change). Then explain that only one of these two hypotheses, or guesses, is true. The goal

of the investigation is to figure out which hypothesis corresponds to what actually happens

in the body.

If students get really stuck here, they can use the simulator to recall how the organelle should

function, and what happens when it doesn’t.

» If you do this, however, be aware that turning off the cell membrane in the simulator

shows glucose accumulating in the bloodstream. This might give away the answer to

which organelle is responsible for diabetes.

• Inside vs. outside

As students have already discussed that diabetes leads to glucose building up in the

bloodstream, they can get confused about what’s happening inside vs. outside of the cell.

The instructions emphasize that we’re looking at glucose inside the cell, but be prepared to

reinforce this as students will focus on glucose in the bloodstream and not the cell.

• Day 1 conclusion

We encourage you to end day one after each group has conducted its own investigation. View

the results of the checkpoint at the end of this activity to see if any students are still confused

about the hypothesis they were investigating. Prepare students, who have been working in

two researcher teams, to come together the next day to continue the investigation as a class.

Day 2

Conduct a Diabetes Investigation

• Share findings

In day 2, students share their findings with each other. You can pair up students (one from

Research Team 1 and one from Research Team 2) to fill out the competing claims data table or

make this a whole class activity.

• Preparing to gather evidence

Before looking at the simulator to find out where insulin works in the cell, be sure to talk

students through what they should be looking for. They should have a prediction. There’s a

lot going on in the graph, so review what it means if the glucose trend in the simulation goes

up or down.


• The big reveal

Students often focus on the visuals rather than the graph, so we’ve built in an opportunity for

students to run the diabetes scenario on their own as well as an opportunity for you to project

it. Understanding the visual demonstrates the students’ understanding of diabetes, but it’s

important for them to understand the graph results, especially after putting in all the hard work

to create their own! We have also included a concluding video on diabetes and insulin to help

students pull together the investigation at the end.

Diabetes Background

• Diabetes

Diabetes is a disease that afflicts millions of people. In the United States, there are estimated to

be 25.8 million children and adults, or about 8.3% of the total population, who have diabetes.

That’s about 1 out of every 12 people.

There are two types of diabetes that differ in how the body handles insulin. In type 1 diabetes,

the pancreas cells don’t produce enough insulin (see below for more background on insulin),

which leads to a buildup of glucose in the blood. In type 2 diabetes, the body’s cells don’t

respond to the insulin made by the pancreas, which also leads to a buildup of glucose in the

blood. Having too much glucose in your blood is actually toxic and can lead to trouble with your

heart, blood vessels, kidneys, or eyesight, among other complications.

Type 1 diabetes is more common in children. Approximately 1 out of every 400 children

or adolescents will have diabetes (http://www.diabetes.org/diabetes-basics/statistics/).

There might be someone in every class who either has or knows someone who has diabetes.

There’s no cure but there is reliable treatment. Diabetes has been treated with injections of the

hormone insulin since the 1920s.

• Insulin

Insulin is a protein hormone that regulates the amount of glucose in the bloodstream. The

pancreas’ beta cells normally produce large amounts of this protein, which then travels

throughout the body via the bloodstream.

On many kinds of cells, primarily muscle and fat cells, there are other proteins embedded in

the cell membrane that accept the insulin protein from the blood. When these insulin receptor

proteins are triggered by the presence of insulin, it prompts the cell to add more glucose

transport proteins to the cell membrane — leading to more uptake of glucose into the cell.


Insulin works like a key, unlocking channels in the cell membrane through which glucose

can pass. Without enough insulin, there aren’t enough channels. This leads to a decrease of

glucose inside the cell and an increase of the glucose in the blood.

Scientists knew that insulin could be used as a treatment for diabetes long before we

knew how the proteins actually worked on cells. The first commercial production of insulin

medication started in 1923. We didn’t discover the molecular action of insulin as a signaling

protein until 1949.

During this 27-year period, the prevailing thought among scientists was that insulin was an

enzyme somehow involved in glucose metabolism — that is, we thought insulin somehow

directly helped the mitochondria produce ATP.

• Discovery of Insulin Action

It was an experiment by Dr. Rachmiel Levine that overturned the assumption that insulin

worked on mitochondria inside the cell. Through a careful experiment that looked at the

behavior of a sugar molecule with and without insulin, he was able to show that sugar can

only pass into the cell in the presence of insulin. This discovery helped establish that insulin

impacts the cell membrane and not, as was commonly thought, the mitochondria. From a

biography on Dr. Levine:

“Dr. Rachmiel Levine’s greatest challenge was to prove his theory to the scientific

community. To dispel the ideology that insulin only served in the chemical metabolism of

glucose once inside the cell, Dr. Levine performed the following experiment. He injected

dogs with galactose [a sugar very similar to glucose] and then with galactose plus insulin,

and measured the amount of galactose in the blood. Galactose is similar to glucose, in

that it can be equally transported across the cell membrane, however once inside the

cell, galactose cannot be metabolized like glucose. If successful, the test would show that

galactose could only be transported across the cell membrane in the presence of insulin.

Dr. Levine’s tests proved that galactose collected in the cells and, as a consequence,

galactose levels in the blood dropped.”

— from Dr. Rachmiel Levine, http://www.cityofhope.org/rachmiel-levine-m-d-

Ultimately, Levine and colleagues prevailed and through their research were able to show that

insulin acts like a key on the cell membrane, opening it to allow sugar to enter the cell.



SESSION 5



• Explore and create a model for a plant cell

• Understand the differences between plant and animal cells (and, potentially, the

connections between them)

• Reaffirm investigation and model building techniques

We recommend that Session 5 (including the post-assessment) be taught over two days (a

total of approximately 1.5 hours of class time).

Introduction

• Mapping the organelles — cell membrane

Students will sometimes suggest that only the animal cell has a cell membrane. This is a

good opportunity to talk about the cell membrane and cell wall in plant cells.

• Mapping the organelles — vacuoles

Students may also remark that animal cells have vacuoles. While it is true that some animal

cells contain vacuoles, all plant cells have vacuoles and they are much larger. For this

reason, the vacuole is only included in the plant cell simulation.

• No assumptions

Before students investigate the plant cell in the simulation, remind them that a good

scientist doesn’t make any assumptions ahead of time! Ensure that students don’t assume

that the nucleus, ribosome, and mitochondria take in and produce the same molecules as

they did in the animal cell.


Plant Cell System

• Drawing a model, again

When they first draw an animal cell, students often focus on making their drawings perfect.

Now they draw new models and improve upon anything that needed work last time. Remind

students what makes a good representation of a model. Students may want to draw all

the organelles in the plant cell—remind them that they’re just focusing on the cell wall, cell

membrane, chloroplast, mitochondria, nucleus, and ribosome. They can add the vacuole,

endoplasmic reticulum, and Golgi apparatus should they finish early.

• Inputs and outputs of a plant cell

Students may have a tendency to skip past the inputs and outputs of the cell as a whole once

they have identified water and carbon dioxide as inputs to the chloroplast as both of those are

available from within the cell (the vacuole and the mitochondria respectively). Direct students to

include this cellular input and output in their model.

Compare and Contrast

• Sharing drawings

You may want to hang up these new drawings next to the animal cell drawings, as students

begin to compare and contrast them.

• Photosynthesis

The biggest difference students should notice between the animal cell and plant cell

systems is that plant cells produce and consume their own food. This is a nice jumping off

point to start exploring photosynthesis. The plant cell simulation offers a Shade scenario,

which can be used to investigate photosynthesis in a manner similar to the choking/

starving or diabetes sessions.

A-1© 2014 Amplify Education, Inc.

1. Our bodies are made of , which are made up of many different parts and are the

basic units of life.

2. Animal and plants cells contain specialized parts called , each with a special

function.

3. What is the relationship between our cells and our bodies?

Teacher Guide for

Amplify Cell Structure and

Function Module

PRE-UNIT AND POST-UNIT ASSESSMENTS

a. cells

b. organelles

c. molecules

d. proteins

a. cells

b. organelles

c. spores

d. cavities

a. Our bodies are made up of cells, and cells keep our bodies alive.

b. Our bodies are made up of cells, but cells do not keep our bodies alive.

c. Cells keep our bodies alive, but our bodies are not made up of cells.

d. Our bodies are not made up of cells, and cells do not keep our bodies alive.


4. Which sequence correctly shows the levels of increasing organization in the human body?

(smallest on the left, largest on the right)

5. If an organism is starving, its cells don’t have enough of which molecule?

6. If an organism is choking, its cells don’t have enough of which molecule?

a. organelle › molecule › cell › organs › organism

b. molecule › organelle › cell › organs › organism

c. cell › organelle › molecule › organs › organism

d. organelle › molecule › cell › organism › organs

a. Oxygen (O²)

b. Carbon dioxide (CO²)

c. Glucose

d. Starving will not affect the cells

a. Oxygen (O²)

b. Carbon dioxide (CO²)

c. Glucose

d. Choking will not affect the cells


7. What happens to the cell if the mitochondria stop working?

a. Organelles depend on each other to function normally so the whole cell might stop

working.

b. Organelles do not depend on each other to function normally so just the mitochondria will

stop working and the cell will continue to work normally.

c. The cell will get ATP from nearby cells to keep working normally.

d. The nucleus will instruct other organelles to work more to make up for the loss of

mitochondria.


8. Identify the structure labeled A.

9. Identify the structure labeled B.

a. Nucleus

b. Cell membrane

c. Mitochondrion

d. Ribosome

a. Nucleus

b. Cell membrane

c. Mitochondrion

d. Ribosome


10. Identify the structure labeled C.

11. Identify the structure labeled D.

12. In a cell, the nucleus .

13. In a cell, the ribosomes .

a. Nucleus

b. Cell membrane

c. Mitochondrion

d. Ribosome

a. Nucleus

b. Cell membrane

c. Mitochondrion

d. Ribosome

a. produces energy (ATP) for other parts of the cell to use

b. builds proteins, the tools of the cell

c. controls which substances can go in to and out of the cell

d. sends out instructions (mRNA) that control the activities of other parts of the cell



c. controls which substances can go in and out of the cell



14. In a cell, the mitochondrion .

15. In a cell, the cell membrane .

16. Which of the following is the best explanation for how the cell gets energy (ATP) for itself?



c. controls which substances can go in and out of the cell




c. controls which substances can go in to and out of the cell


a. The nucleus makes ATP (energy) energy for the whole cell

b. The ribosomes make ATP (energy) from the instructions it receives from the nucleus

c. The mitochondria use glucose to make ATP (energy)

d. ATP (energy) comes from outside the cell and enters in to the cell by crossing the cell

membrane


17. Which of the following is the best explanation for the role that oxygen plays in the cell?

18. Which of the following is the best explanation for how the cell builds proteins?

19. Which of the following is the best explanation for how the cell controls what enters the cell

and what leaves the cell?

a. Oxygen enters the cell by crossing the cell membrane and then gets used by the

mitochondria to make ATP molecules.

b. Mitochondria release oxygen into the cell when they make ATP.

c. Oxygen controls the amount of glucose that can enter the cell.

d. Oxygen combines with carbon dioxide to make glucose.

a. The mitochondria assemble proteins from instructions they receive from the nucleus.

b. The ribosomes assemble proteins from instructions they receive from the nucleus.

c. The nucleus contains the instructions and so proteins get built inside the nucleus.

d. Proteins are made outside the cell and the cell gets proteins when they cross the cell

membrane and come into the cell.

a. The nucleus decides what comes into and leaves the cell.

b. Ribosomes let molecules into and out of the cell.

c. Mitochondria allow molecules into and out of the cell.

d. The cell membrane allows some molecules to enter the cell and some molecule to

leave the cell.


20. Which statement best explains how the nucleus relates to the ribosomes?

21. Which statement best explains how the cell membrane relates to the mitochondria?

22. Insulin is a type of .

a. The nucleus stores instructions in the form of ribosomes.

b. Ribosomes make proteins using instructions they received from the nucleus.

c. The nucleus sends proteins to the ribosome.

d. The nucleus and ribosomes don’t relate to each other.

a. The cell membrane makes proteins that help the mitochondria function.

b. The cell membrane allows mitochondria to enter the cell.

c. Mitochondria use glucose that the cell membrane allowed to enter the cell.

d. The cell membrane and mitochondria don’t relate to each other.

a. cell

b. organelle

c. food

d. protein


23. In humans, insulin helps cells .

24. In humans, insulin helps the:

25. Without insulin, the amount of glucose inside a cell will .

a. use oxygen

b. remove carbon dioxide

c. attack viruses

d. use glucose

a. nucleus produce mRNA.

b. mitochondria use glucose.

c. cell membrane let glucose into the cell.

d. ribosomes make proteins.

a. increase

b. decrease

c. change randomly

d. stay the same

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