Question

Stanley Miller conducted an experiment to demonstrate that simple organic molecules like amino acids could be produced if an electric discharge is passed through a mixture of such gases as might have been present in the atmosphere of early earth The gaseous mixture he used in the experiment comprised

• A. Methane, ammonia, hydrogen, water vapours
• B. Methane, nitrogen, hydrogen, water vapours
• C. Ammonia, carbon dioxide, nitrogen, water vapours
• D. Methane, ammonia, nitrogen, water vapours

Answer 1

The correct option is A Methane, ammonia, hydrogen, water vapours

Miller and Urey provided first proof for chemical synthesis of proteins by amino acids. They simulated the primitive earth conditions as proposed by Oparin and synthesized simple organic compounds (amino acids, fatty acids sugars etc) from a mixture of methane, hydrogen, water vapour and ammonia. As in primitive atmosphere, hydrogen served as reducing agent while methane provided hydrocarbon skeleton for synthesis of organic compounds. Water served as medium for chemical synthesis of organic compounds in the glass chamber. The primitive atmosphere was reducing and did not contain oxygen or any oxide which makes carbon dioxide was absent. The highly reducing primitive atmosphere did not have free nitrogen which presents in the form of ammonia only. Thus, the correct answer is option A.