Question

Formation of most of the amino acids as well as adenine and other nucleic acid bases from inorganic molecules was experimentally shown by

• A. Spallanzani and Pasteur
• B. Hugo de Vries
• C. Oparin and Haldane
• D. Urey and Miller

Answer 1

Answer: (D)

Urey and Miller

In 1953, Stanley L. Miller and Harold C. Urey, working at the University of Chicago, conducted an experiment, which would change the approach of scientific investigation into the origin of life.
Miller took molecules, which were believed to represent the major components of the early Earth's atmosphere and put them into a closed system. The gases they used were methane ($C{H}_4$), ammonia ($N{H}_3$), hydrogen ($H_2$) and water ($H_{2}O$). Next, he ran a continuous electric current through the system, to simulate lightning storms believed to be common on the early earth. Analysis of the experiment was done by chromatography. At the end of one week, Miller observed that as much as 10-15% of the carbon was now in the form of organic compounds, such as adenine and other nucleic acid bases. Two percent of the carbon had formed some of the amino acids, which are used to make proteins. Perhaps most importantly, Miller's experiment showed that organic compounds, such as amino acids, which are essential to cellular life, could be made easily under the conditions that scientists believed to be present on the early earth. Thus, option D is correct.