During photosynthesis, plants convert carbon dioxide into energy-rich substances. In doing so, they release oxygen, which is vital for humans and animals. What is the course of the most important biological process?

Requirements for photosynthesis

Photosynthesis takes place in plant cells. The basis is chlorophyll, the green pigment contained in the leaves. Without the leafy greens, plants cannot produce oxygen. Above all, the trees act as filter systems. They consume the carbon dioxide from the air and produce oxygen.

In addition to plants, algae and some bacteria also use this metabolic process.

Note: Fungi have long been classified as plants. They have no chlorophyll and are unable to carry out photosynthesis. They feed on organic matter.

process of photosynthesis

The term photosynthesis contains the two Greek words “light” and “composition”. It describes the process of transforming low-energy starting products into high-energy substances using sunlight. It absorbs carbon from the atmosphere and water from the soil. As a result of the metabolic process, sugar and oxygen are produced, which form the basis of life for humans and animals.

Note: The percentage of oxygen in the air is 21 percent. This oxygen is only produced by plants.


The formula on which photosynthesis is based is very straightforward and can be explained just as easily.

The equation shown here simply means that six molecules of water (H 2 O) and six molecules of carbon dioxide (CO 2 ) result in six molecules of oxygen (O 2 ) and one molecule of sugar (C 6 H 12 O 6 ). The resulting oxygen is released into the environment, while the sugar is stored.

Note: The sugars formed in the equation are so-called simple sugars, mostly glucose or fructose.

reaction scheme

The biochemical process of photosynthesis takes place in two stages. It is represented in a reaction scheme. The first part, which requires the participation of sunlight, is called the light reaction or primary reaction. The dark reaction describes the second part of the process, which takes place without the influence of light.

light reaction

  • Absorption of electromagnetic energy from sunlight using pigments (chlorophyll or carotenoids)
  • Conversion of electromagnetic energy into chemical energy
  • Transfer of electrons charged by sunlight (redox reaction)

dark reaction

  • Conversion of the substances created by the light reaction into organic compounds
  • Use of the formed substances for growth and energy production of the plant

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *