Curiously thought-provoking

Chemosynthesis and Photosynthesis

Most life on earth requires the sun’s energy.  Organisms that use photosynthesis combine energy from sunlight with carbon to make sugar, forming the basis of most food chains.  However, there are some organisms that don’t have access to sunlight.  How do they get their energy?  They have managed to create sugar from a process similar to but different from photosynthesis, called chemosynthesis.  In the process of chemosynthesis, instead of getting energy from the sun,  organisms get their energy from hydrogen-sulfur bonds.

Photosynthesis is the process of turning light energy into chemical energy and storing it in the bonds of sugar.  Plants need sunlight, carbon dioxide, and water to form a carbohydrate called glucose, or sugar. This chemical, sugar, is the source of energy for all non-photosynthetic life on Earth. Scientists consider  photosynthesis to be the process responsible for the origin of life.  According to Stanley Miller, who performed research on the chemistry of early Earth, various chemicals combined to form the first life. This life depended on a source of energy, or electricity (by lightning).  Eventually, the first forms of life depended on light as their source of energy.  This is still true today, as most organisms depend on the sun’s energy as their source of energy, either directly or indirectly (indirectly by consuming other organisms that use photosynthesis).

Chemosynthesis is the process by which deep sea organisms (that do not have access to sunlight), convert carbon dioxide into sugar. This process takes place primarily in deep-sea hydrothermal vents. Rather than using sunlight as their source of energy, deep-sea organisms use sulfur-rich chemical bonds as their source of energy.  After the discovery of chemosynthesis in 1890 by Sergei Nikolaevich Vinogradskii, scientists began to consider the possibility that life may have began in these hydrothermal vents instead of  with organisms that use photosynthesis at the Earth’s surface.

Both chemosynthesis and photosynthesis use a form of energy to create energy-rich chemical-bonds. They both use carbon dioxide as a source of carbon, however chemosynthesis uses sulfur bonds as it’s source of energy, where as photosynthesis uses the sun’s light as it’s source of energy.  Sugar is the chemical that stores the energy produced in both processes. Photosynthesis only takes place in the presence of light while chemosynthesis takes place in the absence of light.  Both processes are the basis of food chains.  Without either process no other forms of life could exist.  Since chemosynthesis and photosynthesis convert energy into usable forms they make primary consumption possible.  Chemosynthetic organisms cannot photosynthesisize, and vice versa.  Photosynthesis and chemosynthesis both contain water and oxygen in the reactions involved.  Photosynthesis’s chemical formula is 6H2O+6CO2—-C6H12O6+6O2.  The chemical formula for chemosynthesis is  6CO2+6H2O+3H2S—-C6H12O6+3H2SO4.

Photosynthesis and chemosynthesis have many similarities and differences. Both are processes used to create  glucose. Both serve as the basis of all food chains on earth.  Photosynthesis requires sunlight as it’s source of energy,  while chemosynthesis does not.  Chemosynthesis uses sulfur-rich bonds as it’s source of energy. They have two different chemical formulas.  Chemosynthesis takes place deep in the ocean near hydrothermal vents, and photosynthesis takes place on the surface of the Earth where sunlight reaches. The most important similarity of all, both are essential processes necessary for life on Earth.