What are Photosynthetic Organisms?

The Photosynthetic organisms Are those capable of capturing solar energy and using it for the production of organic compounds. This process of energy conversion is known as photosynthesis.

These organisms are able to make their own food from solar energy. These include higher plants, some protists and bacteria, which can convert carbon dioxide into organic compounds and reduce it to carbohydrates.

One of the photosynthetic organisms: algae

The energy required for this process comes from sunlight, which promotes the activity of photosynthetic organisms for the production of organic compounds and carbohydrates, which are used by heterotrophic cells as an energy source.

It is important to note that most of the food consumed daily and the fossil fuel found in nature, are products of photosynthesis.

Photosynthetic organisms are considered primary producers within the trophic chain, since among them they are those that produce oxygen that are the green plants, the algae and some bacteria.

But there are also organisms that are photosynthetic and do not produce oxygen, among them are purple sulfur bacteria and green sulfur bacteria.

What are photosynthesis and what are photosynthetic organisms?

Photosynthesis is the process by which plants, some algae and bacteria are able to produce glucose and oxygen, taking carbon dioxide and water from the environment. The energy needed for this process to occur comes from sunlight.

What are Photosynthetic Organisms? Photosynthesis. Education. (S.f.). Image via photosynthesiseducation.com

As seen in the picture, the plant takes carbon dioxide from the environment, and with the participation of sunlight and water, it returns oxygen to the environment.

The upper floors

The upper plants are plants that are known as vascular plants or tracheophytes, as they have some tissues for the conduction of water through them and others that allow the passage of the products of photosynthesis.

These plants have in their leaves, structures called chloroplasts, which have a pigment called chlorophyll, they absorb sunlight and are responsible for photosynthesis to occur.

The higher plants, as well as some types of bacteria, are called primary producers, since they are capable of producing organic matter like glucose, breaking the inorganic (carbon dioxide) through the process of photosynthesis.

These producers are called autotrophic organisms and represent the point of departure for the circulation of nutrients and energy in the food chain, since the carbohydrates and other chemicals they produce serve as food for the primary consumers who are herbivores.


As well as higher plants, these organisms are Eukaryotes , Ie they are organisms whose cells have a nucleus and organelles inside their membranes. Many of these algae are unicellular, but sometimes they can form large colonies and behave like plants.

Among the structures that these eukaryotic organisms have are chloroplasts, which are organized subunits whose main role is to carry out the process of photosynthesis, which as in plants, chlorophyll captures the energy from sunlight to convert And store it.


The Cyanobacteria , Are prokaryotic organisms, this means that they are unicellular organisms that do not have nucleus, but can behave just like the organisms that realize the photosynthesis.

Although they do not contain organelles such as algae cells, they have a double outer system and an internal one with a thylakoid membrane so they can carry out photosynthesis.

These organisms can produce oxygen from their photosynthetic reactions, because they use water as an electron donor, unlike other bacterial organisms, which perform a type of photosynthesis called anoxigen.

Sulphurous purple bacteria

They are organisms with a very versatile metabolism, since they can use a variety of compounds to obtain electrons and although they do not produce oxygen in their photosynthetic reactions, they have no problem to survive if oxygen is not present.

In case that the conditions of the environment favor the change of their metabolism to a way of life photosynthetic, they begin to add to their cytoplasmic membrane system, more layers, so that later it becomes an intracytoplasmic membrane, which is necessary so that Photosynthesis occurs.

Sulphurous green bacteria

This type of bacteria does not have mobility, but can have multiple forms, among which are the spiral, spheres or rods. They are located at the bottom of the oceans and survive the lack of light and warm wind.

These bacteria, carry out the photosynthesis process in their plasma membrane, without causing any additional alteration to the same, since they have vesicles to adjust their depth and thus get better illumination and use the sulfur as an electron donor, its photosynthesis is anoxigenic.


They are anoxic phototrophic bacteria whose discovery is recent. They contain bacteriochlorophyll g, which is a pigment unique to their species, allowing it to absorb different frequencies unlike other photosynthetic organisms.

They are Gram-positive bacteria and the only ones of them being able to carry out phototrophy. further Are also capable of forming endospores. They are photoheterótrofas, since they obtain the energy of the solar light, but the carbon they take it exclusively of organic sources, in addition they are anaerobic.

It should be borne in mind that life on earth depends mainly on the solar energy, Which is transformed into glucose and oxygen by the process of photosynthesis, which is responsible for the production of all organic matter.

This organic matter is present in the composition of foods consumed daily, in fossil fuels such as oil, trees and raw materials used in industries.

The process of photosynthesis is necessary for life to exist on the ground, since without the production of oxygen that is secreted through the pores of the leaves of plants, it is unlikely that the metabolism of the animals can lead to cape.

That is why it is said that photosynthesis is a process that has far reaching implications, because like plants, humans and other animals depend on the glucose that in this process is generated as an energy source. Hence the importance of photosynthetic organisms.


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