Cells Need the Energy from Food
How to Teach Cellular Respiration to Kids
By Timothy Banas, eHow Contributor (This lesson was adapted from the original.)
One of the first things kids are taught about the relationship between plants and animals is that plants provide
the oxygen that animals need to breathe. This usually creates the impression that plants do not need oxygen, but
nothing could be further from the truth. Plants need oxygen every bit as desperately as animals. Plant cells, like
animal cells, carry out the process of cellular respiration that uses oxygen to convert the energy from foods into
the chemical form used by the cell, ATP. You can teach kids the basics of cellular respiration, and dispel the
myth that plants don't need oxygen, with a simple activity.
6.3.6 Recognize that food provides the energy for the work that cells do and is a source of the molecular
building blocks that can be incorporated into a cell’s structure or stored for later use.
Instructions
Things You'll Need






5 Tennis balls
5 Racquet balls
5 Textbooks
Paper
Markers
Tape
1 Explain to the students that the classroom is a plant cell, the tennis balls represent molecules of oxygen,
the textbooks represent food molecules and the racquet balls represent molecules of ATP (ATP is a
molecule that temporarily "stores" energy and when released provides the energy needed for the cell’s
activities. It may be helpful to think of ATP as a battery that gets charged, and as soon as it is charged, it
sets off a spark of energy that can be used to do work in the body.
2 Assign five students to be mitochondria, five students to be chloroplasts and five students to be oxygen
carriers. Have them make signs that reflect their roles and tape them to their backs.
3 Give each mitochondrion student a racquet ball and ask him to put it in his pocket. Give each chloroplast
student a textbook, and each oxygen carrier a tennis ball. Send the oxygen carriers into the hall and tell them
that you will let them know when to come in and give their oxygen molecules (tennis balls) to the
mitochondria students.
4 Explain that in a plant cell, chloroplasts make food through photosynthesis and oxygen enters the cell
from the air surrounding it. Both the oxygen and the food molecules go to the mitochondria, where they are
both used in a series of chemical reactions--called cellular respiration--to create ATP molecules.
5 Turn off the classroom light. Then turn it back on and explain that photosynthesis has begun. Instruct the
chloroplast students to hand off their food molecules (textbooks) to the mitochondria students.
6 Instruct the oxygen carriers to bring their oxygen molecules (tennis balls) into the plant cell (classroom)
and hand them to the mitochondria students.
7 Instruct the mitochondria students to throw their ATP molecules (racquet balls) around the room as soon
as they receive an oxygen molecule and piece of food. They should store the textbooks and tennis balls
under their desks. The loose racquet balls symbolize the energy molecules that mitochondria release into the
cell for use in metabolic processes.
8 Let the students perform this process on their own a couple more times. Once they see this simple and
hands-on illustration of how mitochondria use the raw materials of oxygen and food to produce ATP
molecules, they are not likely to forget it.
Tips & Warnings
 Note that
the numbers of oxygen, food and ATP molecules used in this demonstration do not accurately
reflect the numbers used in cellular respiration. Using accurate numbers would complicate the activity
beyond what is necessary to illustrate the point. The true numbers can be taught later.