Photosynthesis is a unique process of creating organic substances from inorganic ones. This is the only process on our planet associated with the conversion of the energy of sunlight into the energy of chemical bonds, contained in organic substances. In this way, the energy of the sun’s rays received from outer space, stored by green plants in carbohydrates, fats and proteins, provides the vital activity of the entire living world – from bacteria to humans. Outstanding Russian scientist of the late XIX – early XX century. Clement Arkadievich Timiryazev (1843–1920) called the role of green plants on Earth cosmic. He wrote: All organic substances, no matter how diverse they are, wherever they occur, whether in a plant, in an animal or in a person, passed through the leaf, originated from the substances produced by the leaf. Outside the leaf or, rather, outside the chlorophyll grain, there is no laboratory in nature where organic matter would be released. In all other organs and organisms, it transforms, transforms, only here it is formed again from inorganic matter.
Accumulation of organic matter
All living organisms can live only by consuming in the form of food the energy that green plants received from the Sun with the help of chlorophyll and enclosed in carbohydrates and other organic compounds. Carbohydrates are an important product of photosynthesis.
Example: Many plants, such as sugarcane, sugar beet, onions, peas, corn, grapes, dates, store sugar in the stems, roots, bulbs, fruits and seeds. It is sugars that serve as the main source of energy for all living things, since they can easily become one of the most active compounds in any living cell.
Plants constantly absorb energy in the form of solar radiation and accumulate it. The accumulation of energy is a very important phenomenon for living nature, due to the photosynthesis of green plants.
Example: organic matter is an excellent energy carrier. Man makes extensive use of gas, oil, coal, firewood – all these are organic substances that release the energy that was once introduced into green plants during combustion.
Ensuring a constant carbon dioxide content in the atmosphere
In the Earth’s atmosphere, carbon dioxide is 0.03% of the air volume. This value has been retained for many millennia, despite the fact that a great many living organisms release carbon dioxide during respiration. Even more of it is released during the decay and destruction of dead bodies, during volcanic eruptions, during fires, during fuel combustion. All this huge amount of carbon dioxide is absorbed by green plants in the process of photosynthesis, maintaining a more or less constant content of carbon dioxide in the Earth’s atmosphere and thereby ensuring the possibility of life on our planet.
Oxygen accumulation in the atmosphere
In ancient times, when there were no plants on our planet, there was no oxygen in the atmosphere. At present, atmospheric oxygen in the atmosphere occupies 21% of its volume. The modern gas composition of the atmosphere was formed due to the process of photosynthesis. Thanks to this, all organisms on Earth – bacteria, fungi, animals, humans and plants themselves – can breathe and carry out their life processes.
Ozone is formed from oxygen at an altitude of about 20 km above the Earth’s surface under the influence of solar radiation. It traps that part of the ultraviolet rays that have a detrimental effect on living organisms. The ozone layer that surrounds the Earth creates an opportunity for the life of organisms.
Creating soil on earth
Organic matter formed by green plants is consumed by living creatures of the land. Waste from the processes of vital activity of organisms, products of decay and decomposition of dead bodies (plants, animals, fungi, bacteria) and their individual parts (fallen leaves, dead roots, root hairs, abundant root secretions), falling into the upper layer of the earth’s surface, decompose there and take participation in the creation of a unique natural formation – soil.
Soil is formed and develops on the surface of the Earth as a result of the interaction of elements of animate and inanimate nature. No soil is formed without organic compounds. Soil fertility depends on the amount of organic matter – humus.