Los Angeles Charter Schools Science Partnership
Model-Based Inquiry Lesson Plan
Lesson Title: Cellular Respiration
Topic/ Focus Area: Respiration in Living Yeast Cells
Subject or Grade Level: 7
Major Concept of Lesson:
Cellular respiration is a process and can be observed in organisms such as yeast cells through
their production of carbon dioxide gas.
Model – How will students demonstrate their understanding of the major concept?
Students will discuss ideas about what happened in the yeast flask and come up with
diagrammatic (or pictorial) and written models to explain the phenomenon of cellular respiration.
They will have opportunities to see another model of the cellular respiration process through the
Flash Card Activity, in which they build the cellular respiration chemical reaction using cards.
California Standard(s) to be addressed:
This lesson supports the concept of cellular respiration, which is part of the following standard:
Grade 7 Life Science
1d: Sts know that mitochondria liberate energy for the work that cells do and that chloroplasts capture
sunlight energy for photosynthesis.
Student Objectives:
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Students will conduct a yeast respiration investigation, make observations, and come up with a
model to explain what happened.
Students will compare yeast respiration using sugar and “no sugar” (measure balloon diameter),
and thus determine the role of sugar in the respiratory process.
Students will “build” a chemical reaction illustrating the process of cellular respiration using flash
cards, and compare this model with their original models.
Students will compare the processes of cellular respiration and photosynthesis using the same
flash cards.
Materials and Resources: (references; web sites; science equipment and supplies, etc.)
Per group: Yeast, water bottles (8-10 oz), med/large sized balloon, spoon, tray, sugar
One Flash Card set
Class: warm water (can be kept warm in a hot pot)
Copies: Lab guide, Cellular Respiration Powerpoint, Exit quiz, Cellular Respiration Note-taking
Guide
Lesson Implementation Logistics: (time; mechanics; preparation; safety; lesson preceding/following, etc.)
1. Prior to this lesson, students should have received instruction in
 cells and cellular organelles, in particular the mitochondria
 the process of photosynthesis, as students will be comparing cellular respiration with
photosynthesis in the Elaborate section of this lesson.
2. This lesson was designed for a 90 minute session, but realistically it can easily take 2-3 days
since the need to do the activities to reinforce and practice concepts requires more time.
3. Helpful Hints for the Yeast Investigation:
a. We recommend using a yeast/warm water paste mixture when introducing the yeast to
students so that later on they do not think water is an important reactant in the respiration
reaction. It is an important product, not reactant! We add the warm water only to speed up the
reaction. Make sure water is warm for good results!
b. Use large-sized balloons. Those with a smaller rim tend to tear over the flask opening.
c. All groups can do both set ups (“with sugar” and “no sugar”) OR groups can do “with sugar”
while teacher does a matching number of “no sugar” tests. We do not recommend that some
groups do “no sugar” as they won’t get to observe the dramatic results obtained with sugar.
Vocabulary: Cellular respiration, mitochondria, organelle, organism, process, ATP,
glucose/sugar, carbon dioxide, yeast cells, process
Review:energy, photosynthesis, chloroplasts, chemical reaction, model
Steps of the Lesson
Learning Activities
which lead to Model:
Teacher Questions
for Activity:
Inquiry-Based; ELL and or
Literacy Strategies; Scaffolding
Key questions that show
progression from lower to
higher order thinking.
ENGAGE
1. Examination of Yeast
T distributes lab materials to
each group. Materials
include:
 Yeast
 Flask or water bottle
 Balloons
 Spoons
 Sugar
2. Students write
observations, including
microscopic examinations, in
their lab sheets/notebook.
EXPLORE
Anticipated
Student
Responses,
Questions and
Errors:
Teacher Response to
Students and Teacher
Intervention Activities
or Strategies
Engage:
Engage:
Engage:
Ss will respond to the
following prompts on
their lab sheet:
1.“Pass the baggie of
yeast around the
group. Describe what
you see, what you
feel, and what you
smell. Be as
descriptive as
possible.”
2. What do you think
yeast is? What kind
of an organism is it?
How many cells
make it up? Since we
have been studying
respiration, what
investigation do you
think we might be
doing?
“Smells like bread”
“Smells like
alcohol”
Ss get antsy and act
the fool
Establish protocols for
handling of materials.
Explore
Explore
Adding too
little/too much
sugar and/or yeast
Balloon breaking
Establish groups and work
habits/expectations early;
Establish different roles for
groups (i.e. resource
manager, cleanup manager,
desk manager, etc.).
Measure out materials or
expect to use rough
estimates (i.e. use of “1 flat
spoonful of yeast/sugar”)
Paper towels to clean up
spills
Extra balloons in case any
break
Explore
Part 1. Background
Information and Review
for Students
T shows powerpoint on the
following topics:
 Cellular Respiration
 Raw
materials/reactants
 Products
 Organisms involved
 Organelle involved
Review the topic of
cellular respiration. Make
connections between
organisms.
“What types of organisms
are there?”
“What do they need to
live?”
“Are you an organism?”
What do you need to
live?”
“What do we breathe in?”
“What do we breathe
out?”
(Make connections
between plants and what is
created during
photosynthesis.)
“Plants and
animals”
“Water, air, food,
shelter”
“Air” “Oxygen”
“Air” “Carbon
dioxide”
Prior teaching required with
vocabulary
Use of flashcards with key
vocabulary
Practice the association of
chemical formulas with the
names
Discuss why plants need
energy to grow, to
reproduce, etc.
“Do plants need to
conduct respiration?”
“Why do they need
energy?”
“What organelle is
responsible for releasing
energy?”
Teach the different types of
organisms (animals, plants,
fungi, and protista)
“To grow”
“Chloroplast”
“Mitochondria”
Discuss the different roles
of organelles. (Associate
with “photosynthesis” –
‘making with light’ with
chloroplast.)
Assist Ss with coming up
with different ways to
construct models.
_____________________
Part 2
a. Introduction to the Lab:
Teacher explains and
demonstrates how to do the
lab. Reminds S to refer to lab
handout for further
instructions as they do lab.
b. Ss conduct the lab on
Cellular Respiration in
Action
 Ss make
observations and
draw figures/models
in their lab
document.
 Ss use their senses to
observe the changes
taking place in the
Reflect: What do you
think is going to
happen when sugar is
added to the yeast?
Why do you think
this is going to
happen?
“Put water in the
flask” “Mixed the
T gives guiding
liquid” “Put the
questions regarding
balloon on the top”
the flow of materials
Misconception
during cellular
might be: “Water
respiration while
was needed for
circling the room.
cellular respiration”
“Water activated
“How did we set up
the yeast”
the lab?”
“Air”
Direct/remind Ss about the
function of the warm water
to activate the yeast
flask.
Possible Extension Labs:
 Catching Your
Breath (blowing into
the BTB) and
making
observations; trying
to filter CO2 from
balloon into the BTB
to see the product of
cellular respiration
from yeast
 Blowing into a
balloon and making
comparisons
between the falling
patterns of the yeast
CO2 and Ss’ CO2
EXPLAIN
1. Students generate a
model to explain what
happened
(diagrammatic, written)
a. Discussion in
Groups-Ss will
discuss in groups to
make conclusions
about what has
happened and the
process involved
b. Diagram-Ss will
make a diagram of
the process.
c. Written
ConclusionSs work collaboratively to
make their conclusion in
writing about what process
has occurred. Ss use key
vocabulary to answer
questions about the lab
2. Teacher ExplanationT reviews the lab with the
whole class to go over the
conclusion questions to
ensure mastery and
comprehension.
“What was the
function of the
water?”
“Heat” “Air”
“Carbon dioxide”
Extension activities (see
left column)
“What else was in the
flask before we
closed it?”
“Light it on fire”
(See two extension
activities)
Explain:
Explain:
Explain:
“What do you think
caused the balloon to
expand if no more air
was able to get in?”
“How can we test if it
is really CO2 inside
the balloon?”
Ss may be confused
about the
vocabulary if they
have not rehearsed
its use or discussed
it with classmates.
T lists vocabulary on the
board for S reference
during the written response
T monitors S
progress and checks
responses
MODEL:
T: We all came up with
different models, or
representations, of what
we think happened to
blow up the balloon
(i.e. cellular
respiration). Let’s share
some of those models.
Later on, we will see
another model for
3. Flash Card Student
Activity –
For added reinforcement, Ss
can use flash cards to show
the basic chemical reaction
for cellular respiration
(color-coded cards).
4. Play-Ss can act out the
play “Tyrone’s Track Meet:
A Cellular Respiration
Story” to deepen
understanding about the
importance of each reactant
in the process.
cellular respiration.
Prep the flashcards (colorcoded?). Ss to rearrange
and put into the different
reactions.
Flash Card Activity:
With the flash cards, we
can set up the reaction
for the process of
cellular respiration. The
written reaction is a
model, showing what
goes in and what comes
out, or what is
produced. How is this
model different from
the one you created?
Are there limitations to
the reaction model?
(Yes,it typically doesn’t
show where in an
organism or a cell the
respiration takes place!)
ELABORATE
Elaborate
Elaborate
Elaborate
1. Group Flash Card
Activity to Connect
Photosynthesis with
Respiration
Photosynthesis Flash Card
Order  Cellular
Respiration Flash Card
Order
Teacher models
photosynthesis
equation using large
flash cards. “What is
the equation
showing?”
“Photosynthesis!”
or “Cellular
Respiration”
Revisit products and
reactants. “This is the
process that stores energy.”
2. Individual Flash Card
Activity
Teacher models
cellular respiration
equation using large
flash cards. “What is
the equation
showing?”
Individual flash card
activity:
“Show me the
process of
photosynthesis.”
“Breaks down sugars and
releases energy.”
“Cellular
respiration”
Individual flash
card activity:
Misplacement of
products vs.
reactants
“Show me the
process of cellular
respiration.”
“Opposite”
“What do you notice
about the relationship
“Has the same
Individual flash card
activity:
Reactant = Starting
Product = Ending
between
photosynthesis and
cellular respiration?”
stuff”
“The end products
of one begin the
process or reactants
of the other.”
“What side is carbon
dioxide on during each
one”
_______________________
d. Thought Exercise
Teacher poses the
Candy/Orange Tree
question. Ss work in groups
to discuss, agree on, and
write a concise response with
at least 3 reasons to support
their response.
________________
________________ ______________________
“Would you rather be “CANDY!”
“Does candy help you to
locked in an air-tight
breathe?”
room full of candy
“Orange Tree!”
for a month or a room
with an orange tree
for a month. You
must pick one!
Why?”
EVALUATE
Evaluate:
Cellular Respiration vs.
Photosynthesis Poster:
Ss prepare diagrams and
illustrations about the
relationship between
photosynthesis and cellular
respiration.
Ss work in groups of
2 to create poster
showing process of
each and their
relationship.