Photosynthesis and Chemosynthesis are two fundamental biological processes that play different roles in sustaining life on Earth. While both processes involve the synthesis of organic compounds, they differ significantly in their energy sources and the environments in which they occur. Understanding the difference between Chemosynthesis and Photosynthesis sheds light on the different strategies organisms use to obtain energy and thrive in their respective habitats.
Photosynthesis is a well-known process used by most green plants and certain bacteria called Photoautotrophs. It uses light energy to convert carbon dioxide and water into carbohydrates while releasing oxygen as a by-product. This vital biological process, powered by sunlight and chlorophyll, not only provides organisms with energy, but also contributes to the oxygen content of the Earth’s atmosphere.
Also Check – Types of Autotrophic Nutrition – Chemosynthesis and Photosynthesis
On the other hand, Chemosynthesis is a unique form of autotrophic nutrition that takes place in the absence of sunlight. In this process, inorganic substances are converted into organic compounds, using chemical energy as the driving force. Organisms that rely on Chemosynthesis, such as various underwater organisms and bacteria that thrive in dark environments, use the chemical energy stored in the bonds of substances such as hydrogen sulphide and methane to produce their own food. Unlike Photosynthesis, Chemosynthesis does not require sunlight or chlorophyll, and sulphur is often produced as a by-product.
Table of Contents
Difference Between Chemosynthesis and Photosynthesis
| Aspects | Chemosynthesis | Photosynthesis |
|---|---|---|
| Definition | The synthesis of organic compounds using energy generated from chemical reactions | The process of synthesising glucose using sunlight as the energy source |
| Characteristics | Occurs in the absence of sunlight, often in deep-sea hydrothermal vents | Requires sunlight for the process to take place |
| Energy Source | Chemical energy stored in inorganic compounds, such as hydrogen sulphide | Sunlight |
| Organisms Involved | Microbes, including bacteria and archaea | Green plants, cyanobacteria, algae |
| Products | Glucose and other organic compounds | Glucose and other organic compounds |
| Pigments Involved | None | Chlorophyll, carotenoids, phycobilins |
| Plastids Involved | None | Chloroplasts (specialised plastids in plants) |
| Oxygen as a By-product | Not released as a by-product | Oxygen is released as a by-product |
| Contribution to Total Biospheric Energy | Lower contribution | Higher contribution |
| Categories | Chemoorganotrophs and chemolithotrophs | Photoautotrophs and Photoheterotrophs |
| Equation | Carbon source (e.g. CO2) + Inorganic compounds + chemical energy → Organic compounds + by-products Please note that the equation for chemosynthesis is more generalised, as the specific inorganic compounds and chemical energy sources may vary depending on the organisms and environments involved | 6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2 |
| Examples | Acidithiobacillus ferrooxidans, Nitrosomonas, Nitrobacter, sulphur-oxidising proteobacteria, aquificales, methanogenic archaea | Green plants, cyanobacteria, algae, Rhodobactor |
Difference Between Chemosynthesis and Photosynthesis – Explained in Details
Difference Between Chemosynthesis and Photosynthesis in terms of Definition
Chemosynthesis: Chemosynthesis is the process of synthesising organic compounds using energy obtained from chemical reactions. It occurs in the absence of sunlight, often in deep-sea hydrothermal vents, where organisms use inorganic compounds as a source of energy.
Photosynthesis: Photosynthesis is the process by which organisms synthesise glucose and other organic compounds using sunlight as an energy source. In the process, carbon dioxide and water are converted into glucose with the help of chlorophyll and other pigments.
Difference Between Chemosynthesis and Photosynthesis in terms of Characteristics
Chemosynthesis: Chemosynthesis takes place in environments where sunlight is not available, such as deep-sea hydrothermal vents. These areas are rich in inorganic compounds that serve as a source of energy for the organisms.
Photosynthesis: Photosynthesis requires sunlight for the process to take place. It is mainly carried out by green plants, cyanobacteria and algae, which have specialised structures such as chloroplasts to capture sunlight and convert it into chemical energy.
Difference Between Chemosynthesis and Photosynthesis in terms of Energy Source
Chemosynthesis: the energy source for Chemosynthesis is chemical energy stored in inorganic compounds such as hydrogen sulphide, hydrogen gas or other chemicals found in the environment.
Photosynthesis: Photosynthesis relies on sunlight as its primary energy source. The chlorophyll pigment in plants and other Photosynthetic organisms absorbs light energy, which is used to convert carbon dioxide and water into glucose.
Difference Between Chemosynthesis and Photosynthesis in terms of Organisms involved
Chemosynthesis: Chemosynthesis is mainly carried out by microbes, including bacteria and archaea. These organisms are adapted to survive in extreme environments such as hydrothermal vents, where they use inorganic compounds to produce energy.
Photosynthesis: Photosynthesis is carried out by green plants, cyanobacteria and algae. These organisms contain specialised structures such as chloroplasts that enable them to capture sunlight and convert it into chemical energy.
Difference Between Chemosynthesis and Photosynthesis in terms of Products
Chemosynthesis: The main product of Chemosynthesis is glucose, along with other organic compounds. Organisms that practise Chemosynthesis use inorganic compounds and convert them into organic molecules for energy storage and growth.
Photosynthesis: The main product of Photosynthesis is also glucose, which serves as an energy source for plants and other Photosynthetic organisms. In addition, Photosynthesis releases oxygen as a by-product.
Difference Between Chemosynthesis and Photosynthesis in terms of Involved pigments
Chemosynthesis: No pigments are involved in Chemosynthesis. The energy for the synthesis of organic compounds comes directly from chemical reactions and not from the absorption of light.
Photosynthesis: Various pigments are involved in Photosynthesis, including chlorophyll, carotenoids and phycobilins. Chlorophyll in particular captures sunlight and plays a crucial role in converting light energy into chemical energy.
Difference Between Chemosynthesis and Photosynthesis in terms of Plastids involved
Chemosynthesis: No plastids are involved in Chemosynthesis. Plastids are specialised organelles in plant cells, especially chloroplasts, where Photosynthesis takes place.
Photosynthesis: Photosynthesis takes place in plastids, particularly chloroplasts, which contain the pigments and enzymes necessary to capture sunlight and carry out the biochemical reactions of Photosynthesis.
Difference Between Chemosynthesis and Photosynthesis in terms of Oxygen as a by-product
Chemosynthesis: Chemosynthesis does not release oxygen as a by-product because it does not involve the splitting of water molecules. The inorganic compounds used as energy sources do not produce oxygen when they are used.
Photosynthesis: Oxygen is released as a by-product of Photosynthesis. In the light-dependent reactions of Photosynthesis, water molecules are split, producing oxygen gas, which is released into the environment.
Difference Between Chemosynthesis and Photosynthesis in terms of Contribution to the total energy of the biosphere
Chemosynthesis: Chemosynthesis has a smaller contribution to the total energy of the biosphere. It occurs in certain environments such as hydrothermal vents and is restricted to certain microbial communities.
Photosynthesis: Photosynthesis accounts for a higher proportion of the total energy in the biosphere. It is the primary process by which solar energy is converted into chemical energy. It provides energy for a wide range of organisms and supports most food chains on Earth.
Difference Between Chemosynthesis and Photosynthesis in terms of Categories
Chemosynthesis: Chemosynthetic organisms can be categorized into chemoorganotrophs and chemolithotrophs. Chemoorganotrophs obtain energy by oxidizing organic compounds, while chemolithotrophs use inorganic compounds as their energy source.
Photosynthesis: Photosynthetic organisms are classified into Photoautotrophs and Photoheterotrophs. Photoautotrophs, such as plants, use carbon dioxide as their carbon source, while Photoheterotrophs use organic carbon compounds obtained from other organisms.
Difference Between Chemosynthesis and Photosynthesis in terms of Equation
Photosynthesis Equation:
6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2
In photosynthesis, the energy source is light energy, usually from the sun, and the main compounds involved are carbon dioxide (CO2) and water (H2O). With the help of chlorophyll and other pigments, green plants, algae, and some bacteria convert carbon dioxide and water into glucose (C6H12O6) as the primary product. Oxygen (O2) is released as a by-product.
Chemosynthesis Equation:
Carbon source (e.g., CO2) + Inorganic compounds + chemical energy → Organic compounds + by-products
In chemosynthesis, the energy source is chemical energy derived from inorganic compounds, such as hydrogen sulphide (H2S), hydrogen gas (H2), or methane (CH4). The specific inorganic compounds used and the by-products produced can vary depending on the organisms and environments involved. The carbon source, often carbon dioxide (CO2), is combined with the inorganic compounds using the chemical energy to produce organic compounds as the end product. The organic compounds synthesised through chemosynthesis serve as the energy source for the organisms performing this process. Unlike photosynthesis, there is no direct involvement of light energy or the release of oxygen as a by-product in chemosynthesis.
Also Check – Where do Plants get each of the Raw Materials required for Photosynthesis
Difference Between Chemosynthesis and Photosynthesis in terms of Examples
Chemosynthesis: Examples of organisms that carry out Chemosynthesis include Acidithiobacillus ferrooxidans, Nitrosomonas, Nitrobacter, sulfur-oxidizing proteobacteria, aquificaeles, and methanogenic archaea.
Photosynthesis: Examples of organisms that perform Photosynthesis include green plants, cyanobacteria, algae, and bacteria like Rhodobactor.
Curious Questions on Chemosynthesis and Photosynthesis
Why can’t plants do chemosynthesis if they run out of sunlight?
- Plants are adapted for photosynthesis, relying on sunlight and chlorophyll. Chemosynthesis requires different enzymes and adaptations not present in plants.
Do any organisms use both photosynthesis and chemosynthesis?
- No known organisms use both; they typically specialise in one process based on their environment and available resources.
Can chemosynthesis occur on land, or is it just an underwater process?
- While commonly associated with underwater ecosystems like hydrothermal vents, chemosynthesis can also occur in other environments, like soils where sunlight doesn’t penetrate.
Is chemosynthesis more efficient than photosynthesis?
- Efficiency depends on the environment. In dark environments where photosynthesis is impossible, chemosynthesis is more “efficient” as it’s the only option for autotrophic energy.
Could humans engineer plants to perform chemosynthesis for space travel?
- In theory, it might be possible with advanced genetic engineering, but currently, it’s beyond our technological capabilities.
Also Check – The Alien Worlds of Hydrothermal Vents
Why don’t all plants use the sun for energy if it’s so abundant?
- Plants evolved photosynthesis to exploit sunlight. Organisms using chemosynthesis evolved in environments without sunlight, adapting to available resources.
What would happen to Earth’s atmosphere if all plants switched to chemosynthesis?
- If plants stopped photosynthesis, oxygen levels would decrease, and carbon dioxide wouldn’t be efficiently removed from the atmosphere, drastically affecting life on Earth.
Can chemosynthetic bacteria survive outside their extreme environments?
- Chemosynthetic bacteria are adapted to specific conditions. Outside these environments, they struggle to compete with other organisms adapted to more common conditions.
How do deep-sea creatures rely on chemosynthesis?
- Deep-sea creatures often depend on chemosynthetic bacteria for food, either indirectly (consuming organisms that feed on bacteria) or through symbiotic relationships.
Why is oxygen released in photosynthesis but not in chemosynthesis?
- Photosynthesis splits water molecules, releasing oxygen. Chemosynthesis uses chemical reactions that don’t involve water, so oxygen isn’t produced.
Could chemosynthesis support life on other planets?
- It’s possible. If extraterrestrial environments have chemical energy sources but no sunlight, chemosynthesis could be a viable way for life to produce energy.
Are there any diseases caused by chemosynthetic bacteria?
- Chemosynthetic bacteria are generally not pathogenic to humans, as they thrive in environments vastly different from the human body.
How did chemosynthesis evolve in bacteria?
- It likely evolved as an adaptation to environments where sunlight was unavailable, allowing bacteria to exploit chemical energy sources.
Can chemosynthetic processes be harnessed for human use?
- Theoretically, yes. Understanding and utilising chemosynthesis could have applications in biotechnology and energy production, especially in extreme environments.
Why is photosynthesis more common than chemosynthesis?
- Photosynthesis evolved in response to the abundant sunlight on Earth’s surface, making it more widespread. Chemosynthesis evolved in niche environments.
What would happen if chemosynthetic bacteria went extinct?
- The ecosystems around hydrothermal vents and other chemosynthesis-based habitats would collapse, affecting biodiversity and the food chain in those areas.
Frequently asked questions on Difference Between Chemosynthesis and Photosynthesis
What is the main difference between chemosynthesis and photosynthesis?
Answer- The main difference between chemosynthesis and photosynthesis is the source of energy. Chemosynthesis uses energy obtained from chemical reactions, usually inorganic compounds, while photosynthesis uses sunlight as its primary energy source.
In which environments does chemosynthesis mainly take place?
Answer- Chemosynthesis mainly takes place in environments where sunlight is not available, such as deep-sea hydrothermal vents.
Also Check – 10 Important Differences between Autotrophic Nutrition and Heterotrophic Nutrition
Which organisms carry out photosynthesis?
Answer- Photosynthesis is carried out by green plants, cyanobacteria, algae and certain bacteria such as Rhodobacter.
What is the energy source for chemosynthesis?
Answer- The energy source for chemosynthesis is chemical energy stored in inorganic compounds such as hydrogen sulphide, hydrogen gas or other chemicals found in the environment.
Also Check – Importance of Photosynthesis
How do the organisms involved in chemosynthesis obtain energy?
Answer- Organisms involved in chemosynthesis use inorganic compounds as a source of energy. They convert these inorganic compounds into organic molecules for energy storage and growth.
Which pigments are involved in photosynthesis?
Answer- Various pigments are involved in photosynthesis, including chlorophyll, carotenoids and phycobilins. Chlorophyll in particular captures sunlight and plays a crucial role in converting light energy into chemical energy.
Also Check – Weird Science: Hydrothermal Vents and Cold Seeps
What are the main products of photosynthesis?
Answer- The main product of photosynthesis is glucose, which serves as an energy source for plants and other photosynthetic organisms. In addition, photosynthesis releases oxygen as a by-product.
Is oxygen released as a by-product during chemosynthesis?
Answer- No, chemosynthesis does not release oxygen as a by-product because it does not involve the splitting of water molecules. The inorganic compounds used as energy sources in chemosynthesis do not produce oxygen when they are used.
Also Check – Name the factors affecting Photosynthesis
Which process contributes more to the total energy of the biosphere: Chemosynthesis or Photosynthesis?
Answer- Photosynthesis contributes more to the total energy of the biosphere compared to chemosynthesis. Photosynthesis is the primary process by which solar energy is converted into chemical energy and supports most food chains on Earth.
Also Check – 13 Important Differences between Photosynthesis and Respiration
Give an example of an organism that carries out chemosynthesis.
Answer- Acidithiobacillus ferrooxidans, Nitrosomonas, Nitrobacter, sulphur-oxidizing proteobacteria, aquificaeles, and methanogenic archaea are examples of organisms that carry out chemosynthesis.
Give two examples of organisms that carry out photosynthesis.
Answer- Two examples of organisms that perform photosynthesis are green plants and cyanobacteria.
