Dr. Stanley Miller, using original laboratory equipment, recreates the 1953 Miller-Urey Experiment.
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In 1953, the Miller-Urey Experiment showed how organic molecules could have been created by the conditions of the early Earth. Chemists Stanley Miller and Harold Urey tried to replicate the environmental conditions believed to exist on Earth some 4 to 3 billion years ago mixing water, ammonia, methane and hydrogen in a closed system of glass tubes and flasks. Electric discharges provided some energy for chemical reactions to happen. Then they waited.
After only a few hours, the experiment successfully created amino acids, building blocks of proteins and essential parts of any living organisms. In a paper published in the journal Scientific Reports, a research team argues that another – previously overlooked – element played a major role in the success of the experiment – the special borosilicate glass used by Miller and Urey.
To test their hypothesis, the study’s authors replicated the famous experiment using the same chemicals and equipment, but switching to tubes and flasks made from a special, non-reactive plastic material. The experiment involved two steps: The original experiment run entirely within the plastic environment, and the experiment with some borosilicate glass fragments added into a plastic flask. Comparing the results, they found that far fewer organic molecules are formed in the absence of any glass.
The researchers suggest two mechanisms to explain how glass helps to create complex organic molecules from inorganic gases and water.
The hot and caustic water circulating in the tubes and flasks corrodes the glass’ surface, releasing silicon-dioxide molecules into the solution. The molecules then act as a chemical catalyst, speeding up reactions between nitrogen, carbon and hydrogen atoms, resulting in the creation of organic molecules.
In addition, millions of tiny solution pits formed by chemical corrosion on the equipment’s surface may act as reaction chambers, forcing atoms together and so boosting the rate at which organic molecules are formed and preserved in the experiment.
Miller and Urey used equipment made from borosilicate glass as this special type of heat-resistant material is commonly used in chemical laboratories all over the world. But the new experiment shows how similar materials may have played a major role in the origin of life on Earth. More than 90 percent of Earth’s crust is made up of silicates, minerals composed predominantly of silicon-dioxide. Weathering of silicate minerals by the corrosive primordial atmosphere and water may provided the right conditions for the assembly of the first building blocks of life on Earth.
Source by www.forbes.com
