Photosynthesis: CO2 & life
Carbon dioxide (CO₂) plays an important role in one of life’s most important processes: photosynthesis. It allows plants to grow, provides oxygen for humans and animals and removes CO₂ from the atmosphere.
PHOTOSYNTHESIS AND RESPIRATION
During photosynthesis, plants, algae and certain bacteria use sunlight to convert CO₂ from the air and water into energy-rich glucose (sugar). Plants use the sugar to grow, and they release oxygen into the air, which most living organisms need to breathe.
Graphics: Werder & Stoll (modified)
The World of CO₂ – Photosynthesis
The infographic shows the process of photosynthesis in a schematic depiction. At the center is a green plant with a pronounced root system in a cross-section of the soil.
Inputs to photosynthesis:
- Sunlight: Shown as an orange sun at the top right
- Carbon dioxide (CO₂): Depicted as gray molecules exhaled by a person (right)
- Water (H₂O): Falls as rain from a cloud and is taken up through the roots
- Minerals and chemical elements: From the soil for plant growth and the chemical reactions of photosynthesis
Outputs of photosynthesis:
- Oxygen (O₂): Released by the leaves, shown as white molecules
- Glucose (sugar) (C₆H₁₂O₆): Produced as food for humans and animals
Depicted elements:
The graphic shows a person exhaling CO₂, a plant with a detailed root system, rain clouds, the sun as the energy source, and soil with minerals. Arrows and molecule symbols illustrate the exchange of substances between the atmosphere, the plant, and the soil.
The illustration demonstrates how plants, through photosynthesis, remove CO₂ from the atmosphere and convert it into vital oxygen and food.
Breathing in turn produces CO₂, which is released into the air and absorbed again by the plants. Without this cycle of CO₂ and oxygen, humans, animals and plants could not live. In addition, plants contain sugar, starch, protein and other nutrients, making them an essential food source for humans and animals.
THE DISCOVERY OF PHOTOSYNTHESIS
In 1771, the researcher Joseph Priestley discovered photosynthesis. He proved that animals and plants need one another to survive. Under a sealed glass bell jar, the mouse needed the oxygen emitted by the plants and the plants needed the CO₂ exhaled by the mouse. Only when they were together could they survive. When they were separate, the mouse lacked oxygen and the plants lacked CO₂.
Interactive exhibit
Photo: Nicola Pitaro
PHOTOSYNTHESIS YOU CAN HEAR – LISTEN AS ALGAE MAKE OXYGEN
You and marine algae are closely connected: they produce most of the oxygen you breathe and absorb the CO₂ you exhale. With light and water, they transform it into sugar to grow — and oxygen for you. This process is called photosynthesis.
Put on the headphones and listen as the algae turn sunlight into life. The sound you hear is an artistic interpretation of their photosynthesis activity.