Question

Describe Miller’s experiment. What conclusion could be drawn from this experiment?

Answer 1

Hint: The miller’s experiment gave the concept of chemical origin of life. He explained how life can be originated by the chemicals with the energy. Many amino acids can be produced from these chemicals which can form a long chain of proteins. Proteins are the building blocks of many other important structures in the body.

Complete answer:
The Miller's experiment or Miller- Urey experiment was a chemical experiment. It was done to find the chemical origin of life. It supports the hypothesis of Alexander Oparin and J. B. S. Haldane that conditions on primitive earth favors the chemical reactions that synthesize more complex organic compounds from simpler inorganic precursors.
It was performed by Stanley Miller and supervised by Harold Urey in 1952 at the University of Chicago. They used reactants such as: water, methane, ammonia, hydrogen and sealed them inside a sterile 5-liter glass flask. It is connected to the 500 ml flask half- full of water. The evaporation induced by the smaller flask and the water vapour allowed it to enter into the large flask. The electrical sparks were fired continuously between the electrodes to stimulate lightning in the water vapour. This atmosphere was cooled again so that the water condensed and trickled into a U – shaped trap at the bottom of the apparatus. After a day, the solution turned pink and after a week of continuous operation it turned into a deep red color. After that, mercuric chloride was added to prevent microbial contamination after removing boiling flask. Barium hydroxide and sulfuric acid is used to stop the reaction.
Miller used paper chromatography, and identified five amino acids present in the solution that are glycine, alpha- alanine, beta- alanine, aspartic acid and alpha- aminobutyric acid. Miller also said that just turning on the spark in a basic prebiotic experiment will yield 11 out of 20 amino acids.
He concluded that life originates from chemicals. He showed that simple organic compounds of building blocks of proteins and other macromolecules can be formed from gases with the addition of energy.

Note: The polypeptide chain of amino acids can form the building blocks for the growth of the organisms. Many other scientists performed experiments on the basis of this experiment. Later it was found that DNA and RNA nucleobases could be obtained through stimulated prebiotic chemistry with a reducing atmosphere.