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What is photosynthesis? »Its definition and meaning

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The Photosynthesis is a process by which plants produce organic substances from water and carbon in the presence of chlorophyll (scavenger solar energy) dioxide. The process of photosynthesis as such was discovered by scientists more than 200 years ago. Joseph Priestly (British chemist, physicist and theologian) published in 1772 a work where he refers to the purifying role of vegetation in nature: " By these discoveries we are sure that plants do not grow in vain but that they clean and purify our atmosphere ".

What is photosynthesis

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This word comes from the Greek and is formed by the term "photo", which is equivalent to light, and by "synthesis", which means compound formation. In the field of biology, photosynthesis refers to the ability of plants to transform the energy from sunlight into chemical energy. This process allows plants to generate their own food.

Photosynthesis process

This process is carried out in the green leaves and stems of the plant, in special structures of plant cells: chloroplasts. These organelles contain chlorophyll, a green pigment that is sensitive to light energy and uses it efficiently to kick-start photosynthesis.

For this process to take place, it is necessary that the stages of photosynthesis be fulfilled; on the one hand the availability of light and the presence of chlorophyll, this occurs while the plant receives light, either natural or from an artificial source, and the other dark, since it does not depend on light.

Light phase

The light phase receives this name because all the reactions that occur during it depend on the presence of light. This is captured by chlorophyll allowing photolysis to take place, a reaction in which water breaks down into hydrogen and oxygen. As a result of this reaction, oxygen is released into the environment and hydrogen is used in other reactions that occur within the same process.

Dark phase

The dark phase receives this name because the reactions that occur in it do not depend directly on light, but this does not mean that it occurs at night. It should be noted that this stage is also defined the Calvin cycle or also called the carbon fixation phase.

This phase requires compounds formed during the light phase, in addition to carbon dioxide that is taken from the environment. The latter combines with the hydrogen released in photolysis and other compounds to form glucose, a simple carbohydrate.

However, for the process to be achieved there is the photosynthesis equation:

Carbon Dioxide + Water (+ Sunlight) → Glucose + Oxygen

Here, the elements that initially intervene are carbon dioxide and water, which are later converted into glucose and oxygen, the formula for photosynthesis being the following:

6 CO2 + 6 H2O → C6H12O6 + 6 O2

This photosynthesis reaction takes place thanks to the incidence of sunlight, which allows the plant to transform carbon dioxide and water into the nutrients it needs (glucose) and into oxygen that is released as waste.

Elements that affect photosynthesis

The photosynthetic activity or speed of the photosynthetic process is influenced by various factors, such as the concentration of carbon dioxide in the atmosphere, temperature, and the availability of water and light.

Below are the elements that affect internally and externally:

Internal factors

Internal factors are mainly based on the composition of the leaves. These involve the thickness of the cuticle, the epidermis, the number of stomata, and the available space between cells arranged in the mesophyll. These elements directly affect the propagation of O2 and CO2 in addition to the loss of water.

When the photosynthetic action is high, a lot of glucose is generated. This is stored as starch in chloroplasts, inhibiting photosynthetic reactions.

External factors

The external factors involved in this process are the following:

  • Light: this element depends on three factors that affect during photosynthesis: quantity, duration and quality. Solar energy has the quality and visibility necessary to stimulate the pigmentation process.
  • Water: it is an important factor and its scarcity creates serious imbalances in photosynthetic cells. The water is absorbed through the roots.
  • Temperature: environmental factors are usually very diverse and can vary throughout the day and year. There are vegetables adapted to cold areas where the process can be carried out even at 0 ° and others to hot areas where photosynthesis has more margin, up to 35 °.

Importance of photosynthesis

The set of reactions that are carried out, thanks to this process, allows green plants to generate that energy and oxygen in balanced ecosystems. If the environment is affected, the amount of oxygen will also be affected. We must remember that there are many living things that need this oxygen to survive, and if plant life is lost, it is easy to deduce what could happen.

To all this, we must add the increase in demand at all levels by humans. Therefore, plant life is increasingly disturbed.

The photosynthesis that gives life to the plant kingdom and allows it to obtain energy from sunlight is also characteristic of humans, Dr. Arturo Solís herrera, director of the center for the study of human photosynthesis, discovered that melanin present in human beings humans is equivalent to chlorophyll in plants but much more efficient.

Melanin generates energy, constantly absorbs sunlight and with that energy breaks the water molecule. (Herrera of doctor Arturo Solís).

Scheme and Images of Photosynthesis

Photosynthesis is the process of food production by plants. For this to be carried out, plants need chlorophyll, which is a green substance that they have in their leaves, for it to be evident, photosynthesis is presented drawing and photosynthesis drawing for children

Frequently Asked Questions about Photosynthesis

What is photosynthesis?

It is a process that plants carry out to make their own food from various elements found in their environment: light, sun, carbon dioxide, and water obtained from the soil or the environment. Plants and trees carry out this photosynthetic process to feed, grow and develop.

What is photosynthesis for?

It serves to feed the plant and the production of organic matter, due to this process the plants renew the air. They allow us oxygen, which is what we are interested in, and they remove carbon dioxide.

What is the function of photosynthesis?

Its most important function is:
  • The transformation of solar energy into chemical energy, which is converted into important nutrients such as: sugars and carbohydrates.
  • The transformation of carbon dioxide into oxygen, which occurs at the time of collecting the carbon dioxide that is expelled by living bodies and transforming it into oxygen to continue the cycle.

What is photosynthesis for children?

For children all living beings have to eat; plants, trees, algae, animals, people, all living things, but only that plants are capable of producing their own food from a process called “photosynthesis”. They need external nutrients like; the sun, carbon dioxide and its roots absorb water, minerals from the soil to carry out photosynthesis correctly.

What are the phases of photosynthesis?

Luminous: it depends on the energy of light to obtain chemical energy in the form of ATP and NADPH, from the dissociation of water molecules, forming oxygen and hydrogen.

Dark: the hydrogen that remains from the light phase (the water molecule has broken down) binds to carbon dioxide (CO2), which generates glucose and other carbohydrates.