Word: amino
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Dates: during 1970-1979
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...ordinary soil bacteria. As they investigated subtilisin's complex structure, the scientists realized that it had a curious similarity to another enzyme, chymotrypsin, common to all vertebrates, including man. While the overall molecular architecture of the two enzymes is quite different, they both have three identical groups of amino acids that form what Kraut calls their "business ends." It is at these spots that the chemicals involved in vital reactions are brought together...
...other words, "nature has invented the same piece of molecular machinery to do a particular job in two separate and independent instances." Kraut speculates that this convergence in the evolution of the enzymes is more than a coincidence. The genetic code and the basic building blocks of life (amino acids and proteins) are already known to be universal, he says. Thus Kraut's discovery is further evidence of what may eventually be accepted as a scientific fact of life: given the same problem, nature will find the same solution...
...molecules of gases recently detected in the far reaches of space - ammonia, methanol, formaldehyde and formic acid - in various combinations. Then, keeping the gases completely free of water, the scientists exposed them to ultraviolet radiation and found that they combined to produce small quantities of some of the amino acids essential to life. Says Wollin: "Perhaps liquid ammonia, with its physical and chemical properties so similar to water, could serve as a solvent medium for waterless life...
...Such examples of chemical evolution are an essential first step in the construction of amino acids and proteins, complex molecules that are the building blocks of life itself. Thus, Weliachew has provided significant support for the belief of a growing number of scientists that the same chemical processes that likely produced life on earth are occurring throughout the universe. "I don't smile at the thought of finding intelligent life in the universe," says Weliachew. "It is a serious matter...
Compared to meteorites which have been analyzed, the moon is extremely lifeless. Some meteorites have as much as five per cent carbon (more than 200 times the moon quantity) and one-the Murchison meteorite which fell in Australia in 1967-contains substantial amounts of amino acids-some of which are biologically active. However, none of these carbonaceous meteorites show any indications of living organisms...