Acting Out Cellular Respiration

1. Acting Out Cellular Respiration Dipl. Ing. Konrad Kaufmann

2. The following illustrated description serves as explanation for the actors. The explanation is arranged into small steps to illustrate what should happen. Accompanying these steps, biochemical simplifications are discussed. Depending on the target group, this explanation can be skipped.

3. A red plush ball with two Velcro fasteners (one hook strip, one loop strip) symbolizes an oxygen atom A small blue plush ball with Velcro fastener symbolizes a hydrogen atom. There are blue plush balls with the same number of Velcro fasteners.

4. A black plush ball symbolizes carbon dioxide. • Carbon dioxide is comprised of carbon and two oxygen atoms. • Despite this, carbon dioxide is only symbolized by one ball, as constructions of more than three balls or fruits fall apart. • Further, carbon dioxide is not split. It is integrated into the molecule, bound in biomass, and released again. For the purposes of the game, the basic make-up of carbohydrates is CH2O. The sugar created during photosynthesis is illustrated with a carbon dioxide atom and two hydrogen atoms.

5. An oxygen molecule is constructed from two oxygen atoms. In order to connect the atoms into molecules, the balls must have both a hook piece and a loop piece.

6. The oxygen transport system and the glucose transporter actors sit next to each other at a table. 6 carbohydrate molecules and 3 oxygen molecules are distributed on the table. The actors sit between the tables so that one arm is on the table with the 6 carbohydrate molecules and 3 oxygen molecules and the other arms rests on the empty table. Behind their backs is another table. This table is empty at the beginning of the game. The actors of the glycolysis enzyme and citric acid cycle (one person) and the respiration cycle enzyme (one person) sit at the empty table. The job of the oxygen transport system is to pick up the oxygen molecules and lay them on the neighboring empty table.  The glucose transporter takes the carbohydrate molecules and also puts them on the neighboring table.

7. The person who plays the glycolysis enzyme and citric acid cycle separates the two hydrogen atoms from the carbohydrate molecules (black plush ball + 2 blue plush balls) In doing so CO2 is released (black plush ball) into the surrounding area and discharged from the cell. During the game the ball remains on the table. WARNING: If using toothpicks these should be removed so as to avoid injury.

8. The two hydrogen atoms are passed on to the person who represents the enzymes of the respiration cycle. • The actor takes the hydrogen atoms and an oxygen molecule placed on the table during the oxygen transport system. • As soon as 4 hydrogen atoms have been adopted, the oxygen molecule and the 4 hydrogen atoms are built into 2 water molecules.

9. These molecules are released into the surrounding area and temporarily remain on the table. • The game has run its short course when all carbohydrate molecules have been used. (Under the current conditions ) • At this point the aha effect enters the scene, namely that a cycle is needed in order to supply breathing organisms (consumers and destruents). • To show this, the actors portraying plants are brought into the game. • Two chairs are positioned for the plant actors at the narrow side of the table at which the glycolysis and citric acid cycle and the respiratory cycle enzyme actors are sitting. • They collect all of the carbon dioxide molecules and water molecules laying on the table and stick together the atoms of the corresponding basic equation of photosynthesis.

10. The hydrogen atoms (blue plush balls) are separated from the water molecules. The remaining oxygen atoms (red plush balls) are connected into pairs (oxygen molecules). The oxygen molecules are placed on the table in front of the oxygen transport system – the oxygen is released by plants into the atmosphere.

11. Carbohydrates are built from the separated hydrogen atoms and carbon dioxide molecules (black plush balls) One CO2is taken and connected to two hydrogen atoms. The carbohydrate molecule is placed on the table in front of the glucose transporter. The plants build oxygen and carbohydrates out of the water molecules and carbon dioxide molecules laying on the table.

12. The cycle is complete Now the acting game can be continued as a cycle. In repeating the game it becomes obvious that the biomass and oxygen on Earth is created through sunlight via photosynthesis, converted into chemically binding energy. It also becomes clear that the oxygen in the atmosphere is released from water. Breathing organisms are dependent on this supply of nutrition and oxygen. It is important to begin with respiration in order to show that without a closed loop cycle breathing organisms could not live. Having begun with respiration, the game can be played further by connecting the simplified portrayal of photosynthesis to complete the cycle. Still better, position a table next to the actors of the glycolysis enzyme and citric acid cycle from the respiration cycle. At this table connect the acting out of photosynthesis, in order to highlight that the energy of all creatures on Earth comes from the sun.