The Theory of Oparin Was developed by the Russian scientist, Alexander Oparin , Notable for his contributions to the theory of the origin of life on Earth.
This prominent biologist and biochemist is particularly known for the"primordial broth", a theory which postulates that the evolution of life starts from carbon-based molecules.
In the early decades of the 20th century, Alexander Oparin, in 1923, suggested that if the primitive atmosphere was reduced (contrary to what was envisaged for oxygen enrichment) and that if there was an appropriate supply of energy, such as ultraviolet light, Then a large variety of organic compounds could have been synthesized.
At the same time, in 1929, before reading about Oparin's theory of the reduction of the atmosphere, the leading biologist Haldane Hypothesized that in the early beginnings of the Earth's atmosphere, it was reduced. This phenomenon could catalyze reactions that could form more complicated organic molecules starting from simple molecules.
Haldane proposed that the oceans serve as a huge furnace where through sunlight or ultraviolet, various chemical reactions could be transformed into an aqueous environment to form a large number of organic compounds.
Haldane made the term"prebiotic soup"or"prebiotic atmosphere"which consisted of an abundant place of methane, ammonium and water. This term became a powerful symbol of the view postulated by Oparin and Haldane about the origin of life.
Postulates of Oparin in the Russian Botanic Society
In 1922, at a meeting of the Russian Botanic Society, Oparin had first introduced his concept of primordial growth of organisms through the elaboration of already formed organic compounds. He made the following postulates.
- There is no fundamental difference between a living being and inorganic matter. The complex combination of manifestations and properties so characteristic of life must have appeared in the process of the evolution of matter.
- The Earth at its beginnings had a narrow atmospheric reduction containing methane, ammonia, hydrogen, and vaporized water, which were the essential materials for the evolution of life.
- As soon as molecules grew and increased in complexity, new properties were incorporated and a new colloidal chemical order was imposed on the organic chemical relationships determined by spatial agreement and the mutual relationship of molecules.
- At this early stage of the evolutionary process, competition, speed of growth, difficulty of existence, and natural selection determined the form of material organization which has become the characteristics of living beings.
Oparin demonstration
Oparin showed how organic chemicals in a solution could spontaneously form droplets and layers, and outlined a way in which basic organic chemicals could be formed within microscopically localized systems (possible precursors of cells) by allowing primitive living beings develop.
Oparin proposed that different types of coacervates might have formed in the main era of the terrestrial oceans, and subsequently have undergone a selection process, eventually leading to life.
Chemical evolution
The conception of the origin of the life of Oparin and Haldane contemplated two evolutionary points: biological and chemical.
Atomic phase
At the beginning of Earth there were innumerable atoms of these elements (hydrogen, oxygen, carbon, nitrogen , Sulfur, phosphorus, etc.), which are essential for the formation of protoplasm. The atoms were segregated into three concentrated masses depending on their weight:
- Heavier atoms (iron, nickel, copper...) were found in the center of the Earth.
- The medium-sized atoms of sodium, potassium, silicon, magnesium, aluminum, phosphorus, chlorine, fluorine, sulfur were concentrated in the Earth's heart.
- The lighter atoms of nitrogen, hydrogen, carbon, formed the primitive atmosphere.
Formation of inorganic models
Free radicals were combined to form inorganic molecules such as hydrogen, nitrogen, water, methane, ammonium, and carbon dioxide. Hydrogen atoms were the most numerous and most reactive in the primitive atmosphere.
Formation of simple organic molecules (monomers)
The first organic molecules interacted and produced simple organic molecules, such as simple sugars (ribose, deoxyribose, glucose...), nitrogen bases (purines, pyrimidines), amino acids, glycerol, and so on.
Large rains had to fall at the beginning of the Earth. When the water fell, it could have dissolved in it and spread its salts and minerals to culminate in the form of oceans. In the oceans a large amount of dissolved compounds such as NH 3 , CH 4 , HCN, nitride, carbide, various gases and elements.
Formation of complex organic molecules (macromolecules)
A variety of amino acids, fatty acids, hydrocarbons, purines and primidin bases, simple sugars and other organic compounds accumulated in ancient seas.
In the early atmosphere, electric shocks, solar energy, sun rays, ATP and polyphosphates could have provided the energy source for the polymerization reactions of organic synthesis.
Miller and Urey Experiment
In 1953, two scientists tested the theory of Oparin and Haldane. Harold Urey and his apprentice Stanley Miller attempted to calculate the chemical consistencies of the atmosphere at the beginning of the earth. They based their calculations on the conception that the first atmosphere was reduced.
To accomplish this goal, they simulated the early conditions of the Earth's atmosphere through a closed system containing water, methane, ammonia, and hydrogen. Harold Urey proposed to his student, Miller, that it was possible to synthesize organic compounds in this type of atmosphere.
Result
The Miller and Urey experiment was immediately recognized as an important milestone in the study of the origin of life.
It was conceived as a confirmation of the Oparin and Haldane hypothesis in which many of the key molecules of life could have been synthesized in primitive earth under the kind of conditions presented by Oparin and Haldane.
These molecules would then have been able to take a key role in chemical prebiotic processes, leading to the origin of life.
References
- Reece, Jane B., and Neil A. Campbell. Campbell Biology. Harlow: Pearson Education, 2011. Print.
- IBM TJ Watson Researcher Center Isidore Rigoutsos Manager Bioinformatics Group, Gregory Stephanopoulos Professor of Chemical Engineering and Biotechnology MIT (2006), Systems.
- Biology: Volume I: Genomics, Oxford University Press, p. 6.
- Simsoup. Simsoup.info.
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- Chem.ox.ac.uk.