Table of Contents
Producers are creatures that can convert gaseous carbon dioxide into simple carbohydrates like glucose. Primary production is the process of creating organic compounds from inorganic carbon sources.
Solar radiation, chemical processes, or heat from deep ocean geothermal vents can all provide energy for this process. Plants are the primary producers on land. Algae and plankton dominate marine productivity.
Types of Producers
Phototrophs and chemotrophs are the two main forms of primary producers. Phototrophs convert carbon dioxide into carbohydrates using the sun’s energy. Photosynthesis is the process that allows this to happen. Later, through respiration, the chemical bond energy in carbohydrates is released and utilised to power metabolic pathways.
Chemotrophs go through a similar process, but their energy comes from inorganic oxidation and reduction processes. Chemotrophs are tiny organisms that live in areas where water and light are limited.
The terms ‘secondary producers’ and ‘tertiary producers’ are occasionally used. Secondary producers are animals that eat plants and so ‘produce’ biomass for their predators. Carnivores that consume other species are sometimes referred to as ‘tertiary producers.’
The consumer can only get 10% of the calories supplied to the producer at each trophic level. As a result, energy pyramids with more than four layers, or ‘quaternary producers,’ are uncommon.
Plants, cyanobacteria, and phytoplankton are the three main types of photosynthetic producers.
Plants range in size from tiny species to massive redwoods that tower over the world. Surprisingly, these diverse species all use the same photosynthesis process.
Photosynthesis takes place in chloroplasts, which are specialised organelles that contain pigments like chlorophyll. These pigments are generally found in light-harvesting complexes, which are a scaffold of membrane-bound proteins.
The pigment loses one electron as a result of light-driven oxidation. The high-energy electron then joins an electron transport chain, where it loses energy as it moves from one protein to the next, accompanied by oxidation and reduction processes.
A proton gradient across the membrane is also fueled by the passage of a charged particle along the electron transport chain.
Together, the proton gradient and the electron transport chain fuel the production of Adenosine Triphosphate, the cell’s energy currency (ATP). By breaking a water molecule and releasing molecular oxygen, the photo-oxidized chlorophyll pigment is restored to its original condition.
Photosynthesizing prokaryotes are cyanobacteria. With a fossil record dating back over three billion years, they are among the oldest living forms to have existed on Earth. Over the course of two billion years, they also contributed to the creation of an oxygen-rich atmosphere, opening the path for the types of life forms we see today.
They were first classed as algae because of their photosynthetic activities, and the name ‘blue-green algae’ is still used informally to refer to these prokaryotes. Endosymbionts such as cyanobacteria are thought to have developed into modern-day chloroplasts.
Membrane protein complexes are also found in the cell membranes of these prokaryotes. Some of these membranes create cylindrical thylakoid sheets, which are similar to chloroplasts’ internal structure.
Because of their similarities, they can be used as model organisms for studying photosynthesis. However, there are some distinctions between contemporary cyanobacteria and plant processes.
One of these stems from the prokaryotes’ marine origin, which necessitates the ‘concentration’ of carbon dioxide in tiny vesicle-bound compartments to increase the effectiveness of photosynthetic enzymes like RuBisCO.
They are essential for the health and survival of marine ecosystems because they contribute to the production of bioavailable carbon and nitrogen. Ammonia is used to fix nitrogen and produce nitrogen-containing molecules like proteins and nucleic acids.
Cyanobacteria are among the most significant marine primary producers because they are eaten by species on the ocean floor, in shallow waters, and in open seas.
Phytoplankton are tiny free-floating plants that carry out the majority of the ocean’s photosynthetic activities. They are the foundation of marine ecosystems and keep the ocean and atmosphere’s oxygen levels in check.
They are eaten by zooplankton, which are small herbivorous creatures that are devoured by species higher up in the food chain. Phytoplankton’s emergence is thought to have aided a massive evolutionary boom 250 million years ago.
Following a catastrophic extinction at the end of the Paleozoic period, more nutrients and less predation allowed these plants to thrive in the seas. Their abundance and improved nutritional content also aided the proliferation of primary consumers such as zooplankton.
Some populations evolved and adapted to new habitats as these groupings of creatures developed and colonised broader ocean tracts, resulting in a huge increase in species variety in the seas.
Producers are the world’s major source of biomass. They are the initial trophic level in every ecosystem and comprise the bottom of all energy pyramids.
Primary producers fix inorganic carbon in the form of carbs using energy from the sun or chemical processes. Their role in sequestering carbon dioxide makes them critical for global weather patterns, ensuring that temperatures and yearly rainfall are kept at ideal levels.
As a consequence of photosynthesis, oxygen is produced, which is used by all organisms in order to release the chemical energy contained in carbohydrates. Lichens, for example, are essential pioneer species, changing the abiotic environment to make it more livable.
They hasten weathering and increase organic matter deposition, resulting in the development of soil. Producers, together with abiotic variables, play a critical role in defining a region’s species diversity.
Filter-feeding herbivores, for example, will thrive when plankton are the major producers, followed by predators that can devour these species.
Regions with towering trees, on the other hand, will encourage herbivores like giraffes that can reach the highest branches, and will then prefer predators who can hunt these fast creatures. As a result, the main producer is the foundation of the entire ecosystem.
Adenosine triphosphate (ATP) is a nucleoside triphosphate with two high-energy links that serves as the cell’s energy currency. Light-dependent processes begin with the photo-oxidation of chlorophyll and finish with the release of molecular oxygen, reduced nucleotides, and ATP on the chloroplast’s thylakoid membranes.
Reaction centres are areas in chloroplasts where a coloured pigment harvests the light energy of a photon and processes it to drive additional chemical reactions, eventually leading to the production of reduced carbohydrates.
RuBisCO is a chloroplast enzyme that catalyses the reaction between carbon dioxide and Ribulose biphosphate, a five-carbon sugar. This is the first in a sequence of processes that turns gaseous carbon dioxide into bioavailable carbon.
- Herbicide Exposure and Toxicity to Aquatic Primary Producers. Rev Environ Contam Toxicol . 2020;250:119-171.
- Plastics: Environmental and Biotechnological Perspectives on Microbial Degradation. Appl Environ Microbiol . 2019 Sep 17;85(19):e01095-19.
- The community and ecosystem consequences of intraspecific diversity: a meta-analysis. Biol Rev Camb Philos Soc . 2019 Apr;94(2):648-661.