Word: amino
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While the geologists, chemists and physicists are busy with their investigations, other scientists will be on an even more exciting quest. Biochemists will be examining the specimens for evidence of amino acids and protein molecules?the building blocks of life. Paleontologists will seek fossil remnants of organisms. At NASA's Ames Research Center at Moffett Field, Calif., still other investigators will try to coax life itself from the lunar rocks, using nutrients in the hope of resuming a life process that might have been interrupted millions of years...
...antibody molecule is a protein, made up of chains of amino acids, of which there are 20 varieties. In 31 years of detailed work, the Edelman team learned by chemical and physical analysis that this particular molecule contains 19,996 atoms (of hydrogen, carbon, nitrogen, oxygen and sulphur) grouped in 1,320 amino-acid units, which in turn are assembled with the aid of chemical bonds into two "light" chains of 214 amino acids apiece and two "heavy" chains of 446 each (see diagram). Schematically, the four chains, in which the acids are strung like beads, look like a letter...
...They Did It. The Rockefeller researchers, Drs. Robert B. Merrifield and Bernd Gutte, began their experiment with a tiny bead of plastic, onto which they hooked a 124-link chain of amino acids. There are 20 different amino acids, and, because all proteins, including enzymes, are made of amino-acid chains, the acids have been recognized for many years as the "building blocks of life." The exact sequence and identity of successive acids in the ribonuclease chain were recently established, and the Rockefeller team's job was to link them, one at a time. The painstaking process involved...
...Merck researchers, Drs. Robert G. Denkewalter and Ralph F. Hirschmann, went at it differently. They prepared groups of six to 17 amino acids in linked series. They then put these groups together to form the ultimate 124-link chain. Their product turned out to be the same as the Rockefeller synthetic enzyme; its identity was proved by the way in which it broke down ribonucleic acid...
...Cornell, Holley studied both the genetic code and its function in building proteins by analyzing "transfer RNA," a form of ribonucleic acid. RNA collects amino acids floating in the cell and, like a tug towing a barge, pulls them to an assembly site where, in the sequence dictated by the master DNA molecule, they are combined into the appropriate protein. Holley worked out the complete structure of a transfer RNA molecule, demonstrating how it attaches to a particular amino acid and brings it to the growing protein chain at the proper time and place...