Acting Out Photosynthesis

Dipl. Ing. Konrad Kaufmann

The following illustrated description serves as explanation for the actors.

The explanation is arranged into small steps to illustrate what should happen.

Alongside these steps, biochemical simplifications are discussed.

Depending on the target group, this explanation can be skipped.

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.

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 but bound by the CO2 fixation in biomass.

Sunlight‘s photons are symbolized by corn kernels. They can also be symbolized by spiral noodles (fusilli).

Tip: The idea of using spiral noodles comes from their shape corresponding to the wave-particle duality.

The plush balls are connected at the Velcro fastener points.

These water molecules are formed from an oxygen atom and two hydrogen atoms.

6 hydrogen molecules and 6 CO2 molecules are spread out on the floor

Free oxygen is not present at the beginning of the game.

The photosystem and antenna pigment actors/actresses stand in the direction of the sun and hold their palms overhead in order to catch the photons.

Their bodies are bound together with a rope.

The sun stands across from them and throws corn kernels or spiral noodles (fusilli) out of a sack in the direction of the photosystem and antenna pigment actors’/actresses’ hands.

The photosystem and antenna pigment actors/actresses hold their hands up and catch the corn kernels or spiral noodles.

This process should illustrate that the energetic power of the sun is only absorbed on a small scale. The chlorophyll molecules only absorb light when the photons hit them.

If time allows, the person who represents the antenna pigments gives the corn kernels to the photosystem, who is also trying to catch corn kernels

The chlorophyll molecules in plants are connected to light collecting complexes that relay absorbed energy.

The hydrogen atoms (reducing equivalents), in which the sun’s energy is now stored as chemical energy are discarded or taken over by the light independent reaction. The corn kernels are let fall – their energy is transformed into chemical energy.

There are no free hydrogen atoms in plants. Hydrogen is bound to NADP and made available for the light independent reaction. Simultaneously, the water splitting creates ATP, which delivers energy for the light independent reaction. As ATP is not visible in the total balance, it has been left out for simplification purposes.

As soon as the photosystem has attained 9 corn kernels (spiral noodles), the actor or actress picks up two water molecules and separates the blue plush balls (hydrogen atoms).

For the separation of two water molecules and the following connection of CO2, 8 photons must be absorbed (in theory). Measurements have shown that in actuality 9-10 photons are required.

The remaining red plush balls (oxygen atoms) are connected into pairs (oxygen molecules).

The oxygen molecules are rolled to the side – the oxygen is released into the atmosphere.

The oxygen set free during the water splitting is released into the atmosphere as an oxygen molecule.

The person playing the light independent reaction enzyme waits near the photosystem until the blue plush balls (reducing equivalents) are released.

From the blue plush balls which have been taken in (reducing equivalents) carbohydrates are formed.

In doing so, a black plush ball (reducing equivalent) is taken on, to which two blue plush balls are attached.

The black plush ball with the two blue plush balls represents a carbohydrate. It is discarded.

The carbohydrate (biomass) is used by plants in forming their physical/anatomical structures or stored, from which to later extract energy.

The light independent reaction is called such because it occurs without light.

In this reaction sequence the energy-rich compounds (NADPH, ATP), created by the water splitting,are used to form glucose.

The formula for glucose is C6H12O6.

In order to avoid creating to large constructions that can not be acted, photosynthesis

is shortened to:

CH2O is the fictitious basic formula for carbohydrates.

The formula sum of carbohydrates is Cn(H2O)m.

Carbohydrates are called such, because in the 19th century it was assumed that the process dealt with a hydrate of carbon.

6 CO2 + 6 H2O C6H12O6 + 6 O2

CO2 + H2O CH2O + 1/2 O2