What is Autotroph?

An autotroph is a type of organisms that produce their own food through the use of diverse substances like sunlight, water and various other chemicals.

The term autotroph is composed of two words, ‘auto’ meaning self and” meaning self, and ‘troph which refers to food. Autotrophs, therefore, are capable of making their own food with no assistance from anyone else. They are also known as ‘producers since they are the foundation of bio-based food chains, and provide all other food items for other living things. They are vital because all living things depend on them to provide energy and food.

The most well-known autotrophs are those of plants. However numerous other types of autotrophs can be found in the natural world, including phytoplankton, algae, as well as some bacteria. Many autotrophs use photosynthetic processes to transform solar power into chemical energy, however some autotrophs also make use of other processes like chemotrophy and phototrophy. The green plants all contain chlorophyll , the pigment that photosynthesizes for the procedure of photosynthesis. Other pigments such as bacterial rhodopsin and carotenoids can be found in some algae, bacteria phytoplankton, and algae for photosynthesis.

A few rare autotrophs create food by the process known as chemical synthesis that derives power from chemical reactions instead of sunlight. Organisms that perform chemosynthesis reside in extreme environments , where toxic chemicals required to perform the reaction are present. The bacteria that live in volcanoes utilize sulfur for their food production. Autotrophs constitute the first level of trophic levels in the food chain. These organisms are later eaten by herbivores that form the second trophic level , and then on. A rise in the number of autotrophs ultimately increases the amount of people who consume them. A decrease in the amount of autotrophs results in starvation to the other levels of trophic level.

Examples of Autotrophs

Green Plants

Green plants constitute the biggest autotrophs group that makes use of sunlight to facilitate the assimilation of organic compounds into organic compounds. Plants have chlorophyll as an organic pigment that can absorb solar energy. This energy can then be transformed into chemical energy by different metabolic pathways. Primarily, herbivores need plants for energy and food and energy, while secondary consumers such as carnivores depend indirectly on green plants indirectly. Green plants are the primary trophic stage of the food chain, and provide the energy needed to be spread throughout the chain. The plants utilize sunlight and carbon dioxide to make carbohydrate (glucose) as well as oxygen.

Green algae

Green algae is a separate kind of organism that is able to produce their own food through photosynthesis. They are photoautotrophs and can be most often found in ponds or wetlands. Like plants, these organisms have chlorophyll as their pigment used to capture solar energy that is required to perform the process. Green algae creates green mats that are found on the ground, which help to provide oxygen to the air.

Nitrosomonas

Nitrosomonas is a family of nitrogen fixing bacteria that transform molecules of nitrogen in an organic state that is consumed by plants living in the soil. They are chemoautotrophs which utilize the energy generated by the chemical reaction to provide a method to prepare food. These organisms absorb nitrogen, and then reduce it to the form of nitrate that can be integrated into plants as amino acids. So, by the process that is involved in nitrogen fixation they get the energy needed to prepare amino acids.

What is Heterotroph?

A heterotroph is an assortment of organisms who get their food from other organisms , and cannot produce their own food.

The word heterotroph is comprised of two words, ‘hetero”meaning others” and “troph which means food. Heterotrophs are also known as consumers because they consume food that is prepared by autotrophs. They are the higher trophic levels within the food chain. Heterotrophs are further subdivided into two kinds according to the energy source from which they derive their energy. Photoheterotrophs get the energy they require from sunlight sources but depend on carbon producers for their sources.

Chemoheterotrophs also receive both their energy and carbon sources from different producers. Certain heterotrophs directly depend on autotrophs to feed such as herbivores that feed on plants. Others heterotrophs indirectly depend on producers through feeding on the same type of heterotrophs. The majority of heterotrophs rely on photosynthesis in several various ways. Apart from providing energy and nutrition, photosynthesis also supplies oxygen to the heterotrophs.

The carbon compounds that are reduced by autotrophs are later converted by heterotrophs to generate energy that is used for the growth of their population and for reproduction. Heterotrophic nutrition can be further classified into three categories: parasitic nutrition, saprotrophic nutrition as well as holozoic nutrition. Saprotrophs are a type of heterotrophs that eat the decaying and dead organic material to provide carbon, energy, and nutrients.

Holozoic organisms belong to a different category of heterotrophs which consume solid food items from other organisms and break it into smaller pieces prior to being transported to various parts in the human body. Parasites are heterotrophs which depend completely upon other species for every form of nutrition. In this situation the parasite benefits in a way that the host is not.

Examples of Heterotrophs

Animals

Animals constitute the bulk of the living organisms that are consumer trophic stage of the food chain. All animals are heterotrophs dependent both directly and indirectly upon plants as well as products for energy and food. Herbivores are primary consumers who directly eat plants and are the primary source of carbon. Carnivores are secondary users who consume herbivores to eat. Animals consume carbon in the form of organic that is later broken down to produce energy for expansion and reproduce. Humans are omnivores and are omnivores, and eat both animals and plants and are heterotrophs.

Fungi

They are heterotrophs and don’t consume autotrophs, but rather absorb their food. They consume nutrients instead of organic matter. The majority of saprophytic fungi live in areas of decaying and dead material as it is a source of simpler energy. They produce digestive enzymes that aid in breaking down food into smaller fragments prior to taking them in for consumption. Certain fungi are parasites and feed on their host not harming host. Fungi are decomposers within the food chain, which helps transfer energy back to the atmosphere for autotrophs to consume.

Differences Between Autotroph and Heterotroph – Autotroph vs Heterotroph

Basis for Comparison	Autotroph	Heterotroph
Definition	An autotroph is one of the groups of organisms that produce their own food using different substances such as sunlight, water and various other chemical compounds.	A heterotroph is a class of organisms who get their food from other organisms , and are not able to produce their own food.
Energy source	The energy source in autotrophs is sunlight or chemical reaction.	Autotrophs are the primary or indirect source of energy for heterotrophs.
Dependency	Autotrophs are self-sufficient and make their own food.	Heterotrophs depend directly, or indirectly upon autotrophs.
The level of the Trophic	Autotrophs are the trophic stage in the food chain.	Heterotrophs make up the third or second levels of trophics within the food chain.
Solar energy	Solar energy is stored in autotrophs.	Storage or utilization of solar energy is not feasible in heterotrophs.
Role	Autotrophs act as producers.	Heterotrophs serve as consumers.
Types	Autotrophs come in two varieties of autotrophs: photoautotrophs as well as chemoautotrophs.	Heterotrophs also come in two kinds: phytotoheterotrophs as well as Chemoheterotrophs.
Organisms	Autotrophs consist of mainly algae, plants and a few bacteria.	Heterotrophs include primarily animals, fungi, as well as certain bacteria.
Photosynthesis	Photosynthesis is the main metabolic pathway that allows for the creation of energy.	Photosynthesis isn’t an issue in heterotrophs.
Photonthetic pigments	Photosynthetic pigments are generally found.	The pigments of photosynthetic origin are not present.
Carbon source	Autotrophs make use of carbon inorganic as their carbon source.	Heterotrophs make use of carbon from organic sources as source of carbon.
Energy source external to HTML0	Autotrophs require external sources of energy such as the sun or reactions with chemicals.	The majority of heterotrophs don’t require the use of a separate source of energy. Photoheterotrophs could utilize sunlight to generate energy.
Availability	Autotrophs create food over the same time. Plants make food throughout the day , while chemoautotrophs rely on chemical reactions.	Heterotrophs can eat at any time of the day.
Examples	Plants, algae, cyanobacteria, etc.	Animals, human beings and fungi, as well as heterotrophic bacteria.