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Correct Answer: amino acids do not form in high quantities.
the miller-urey experiment, conducted by stanley miller and harold urey in 1952, was a landmark study aimed at understanding the chemical origins of life on earth. the experiment simulated the conditions thought to exist on early earth and tested the idea that life's building blocks could form spontaneously through natural processes.
the experimental setup included a mixture of gases that were believed to represent the early earth's atmosphere, which miller and urey composed of methane, ammonia, hydrogen, and water vapor. these gases were circulated through an apparatus that included a flask containing water (simulating the ocean) heated to induce evaporation, and an electrical discharge (simulating lightning) was introduced to provide energy to drive chemical reactions.
the results of the experiment were groundbreaking as they led to the formation of organic compounds, including amino acids, which are the building blocks of proteins vital for life. this supported the hypothesis that organic compounds necessary for life could have formed naturally on the prebiotic earth.
however, the question at hand suggests a different atmospheric composition, based predominantly on volcanic emissions featuring carbon dioxide, water vapor, and traces of ammonia, methane, and hydrogen. in such an environment, the formation of amino acids would be considerably more challenging compared to the original gases used in the miller-urey experiment. the presence of a large amount of carbon dioxide, in particular, poses a challenge because it does not react as readily to form complex organic molecules like amino acids.
the correct answer to the question, therefore, is that amino acids do not form in high quantities in such an atmosphere dominated by carbon dioxide. the volcanic gases, with their high carbon dioxide content, would not be as conducive to the synthesis of amino acids as the reducing atmosphere used in the miller-urey experiment. the energy sources (such as lightning in the experiment) might still catalyze some reactions, but the overall yield of amino acids would be significantly lower.
the false answers provided offer additional insights:
1. "they would tend to break up chains, not build them" - this statement is more relevant in the context of an oxygen-rich atmosphere, where oxidative reactions could lead to the breakdown of organic molecules.
2. "amino acids form in abundance, but not protein chains" - this is incorrect because even the initial formation of amino acids is challenged under the atmospheric conditions described, let alone their assembly into protein chains.
3. "amino acids form proteins, but the proteins are not functional" - this statement assumes that amino acids and subsequent proteins are formed, which is unlikely under the given conditions, making the premise itself flawed.
in summary, the presence of high concentrations of carbon dioxide and the lack of more reactive gases like methane and ammonia in the described volcanic atmosphere would result in the low formation of amino acids, crucial precursors to proteins and essential components of life. this contrasts with the findings of the miller-urey experiment, which highlighted the importance of a reducing atmosphere for the abiotic synthesis of organic compounds.
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