Miller Urey Experiment

How did the miller urey experiment model conditions of early earth

• The Miller-Urey experiment simulated lightning by passing a continuous electrical discharge through a mixture of gases thought to make up the early Earth’s atmosphere.

• They used a mixture of methane (CH4), ammonia (NH3), hydrogen (H2), and water (H2O).

• Organic molecules accounted for as much as 10-15% of the carbon at the end of one week.

• Over 20 amino acids, including 13 of the 22 necessary to produce proteins in living cells, had generated about 2% of the carbon.

• Although scientists now know that the early Earth’s atmosphere was different from that employed by Miller and Urey, their study was groundbreaking.

• It demonstrated that amino acids, which are required for life, can be synthesised from inorganic substances.

Miller and Urey Experiment

An experiment was carried out by Stanley L. Muller and Harold C. Urey to describe the genesis of life on Earth. They believed that inorganic particles may be used to generate amino acids in the early earth’s atmosphere. Methane, water, hydrogen, and ammonia were used by the two biologists as examples of elements found in the early earth’s atmosphere. The chemicals were enclosed inside sterile glass tubes and flasks that were joined in a loop inside the apparatus and cycled.

The water in one flask is half-filled, and the electrodes are in the other flask. The water vapour was heated, and the resulting vapour was introduced to the chemical combination. The gases that were released swirled about the equipment, simulating the atmosphere on Earth. The water in the flask represents water on the surface of the world, while the water vapour represents water evaporating from lakes and seas. The electrodes were used to light the fire in order to simulate lightning and a storm by using water vapour as a medium.

The water condensed as the vapours cooled. In a continuous cycle, the condensed water returns to the first water flask. After a week, Miller and Urey looked at the cooled water and discovered that 10-15% of the carbon was in the form of organic molecules. 13 amino acids were produced from 2% of carbon. Nonetheless, the Miller and Urey tests were panned by their peers.

The Miller-Urey Experiment has been criticised.

The experiment was unable to explain how proteins are responsible for amino acid synthesis. A few scientists have argued that the gases employed by Miller and Urey were not as plentiful as the experiment indicated. They believed that the atmosphere is made up of gases such as oxygen, nitrogen, and carbon dioxide emitted by volcanic eruptions. As a result, the outcomes are suspect.

Haldane and Oparin

Oparin and Haldane proposed in the early twentieth century that if the primitive earth’s atmosphere was decreasing and it had a significant amount of energy, such as UV radiation and lightning, organic chemicals would be created in a wide range.

Organic components, according to Oparin, would have gone through a series of reactions to generate complex molecules. In the aquatic environment, he theorised, the molecules formed coacervates.

The atmosphere of the primordial sea, according to Haldane, was devoid of oxygen and made up of ammonia, carbon dioxide, and ultraviolet radiation. This resulted in a slew of chemical molecules. The sea was described as a “hot dilute soup” because it contained huge levels of organic monomers and polymers. Polymers and monomers, he believed, developed lipid membranes. The molecules continued to evolve and eventually gave birth to the first living entity. Haldane invented the phrase “prebiotic soup.”

Conclusion

Miller and Urey came to the conclusion that the predominantly reducing atmosphere that existed at the time was the basis for spontaneous organic compound synthesis on early Earth. In a reducing environment, electrons are more likely to be donated to the atmosphere, resulting in processes that produce more complex molecules from simpler ones.