Word: amino
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Dates: during 1970-1979
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...life begin on the primordial earth? Scientists looking for clues within the living cell have been stymied by a catch-22. All living organisms are composed largely of proteins, which consist of strings of amino acids manufactured within cells in small granules called ribosomes. But ribosomes are themselves highly complex protein structures that obviously evolved long after protein first appeared. Then how, without the complex ribosome "factories," was primitive protein produced? Last week, in a report published in the journal Origin of Life, a team of molecular biologists suggested an answer. If the hypothesis is correct, says...
...dieting fad but of the oldest, surest and quickest way to get rid of excess fat: fasting. Along with others afflicted with severe obesity, he had enrolled in a pioneering fasting clinic at Cleveland's Mount Sinai Hospital. Except for a powdery mix of mainly alanine (an amino acid) and glucose that is taken with water or diet drinks, patients at the clinic eat nothing whatsoever for weeks and months at a time, starving off their pounds...
...been wiped out; there has been a lot of extinction. Things have settled down to a degree by now, just because we have lived together for so long. I'll tell you how slow evolution goes. To make the usual mutation, which means that one has changed just one amino acid in a protein, and make it become the norm for the species, takes, on the average, six million years. What we're being faced with now is the possibility not only of changing one amino acid in a protein, but of producing whole new proteins overnight across very distant...
...millions of chemical "steps" along much larger DNA molecules, this bacterial gene contains only 199 full steps, each a pair of letters in the genetic code. Consisting of chemicals called nucleotides, these letters make up words in the gene's message-in this case, instructions to transfer the amino acid tyrosine to the cell's protein-manufacturing centers...
...chainlike structure that-like a key fitting into a lock-binds the whole molecule to the mast cell. Experimenting with one segment of the chain, Hamburger finally found and analyzed the structure of the binding part. He then synthesized it, producing a pentapeptide, or chain of five amino acids, that is capable of fitting the binding site on the mast cells. Injected into an allergy victim, the pentapeptide occupies the binding sites on the mast cell and blocks the complete IgE molecule from attaching itself and causing an allergic reaction. Hamburger, who himself suffers from hay fever, then tested...