The structure of the "second genetic code"
Article Abstract:
Molecular biologists at Yale University have made great strides in unraveling the mysterious process of cellular protein synthesis. Previous discoveries have shown that the process begins as the genetic code embodied in DNA (deoxyribonucleic acid) is copied onto messenger RNA (ribonucleic acid). Messenger RNA (mRNA) then displays the plan for proper placement of amino acids to form a new protein molecule; amino acids are the molecular components that make up proteins. Many units of transfer RNA (tRNA) "read" the plan and respond by carrying the individual amino acids to mRNA and arranging them as needed. A critical step occurs when tRNA picks up an amino acid; it needs an enzyme called tRNA synthetase to link to the correct amino acid. There are 20 distinct synthetases corresponding to the 20 amino acids in each cell, and each synthetase must bring the amino acid to only one of 45 to 50 different tRNAs. Since tRNAs all look similar, scientists have wondered how the right pairing of synthetase and tRNA always occurs; if it did not, protein structure would be full of errors which could effectively shut down body functions. The Yale biologists have discovered aspects of the complex process by which the synthetase and tRNA recognize each other; the recognition mechanism has been called the "second genetic code". Findings so far indicate that the two molecules fit together structurally, but the details of how they fit still have to be elucidated.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1989
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The (liquid) breath of life
Article Abstract:
A very premature infant at Saint Christopher's Hospital for Children in Philadelphia was treated with perfluorocarbon after conventional breathing therapies failed and actually caused damage to the lungs. The baby lived 19 hours after the treatment with perfluorocarbon. This was a breakthrough for further study of liquid breathing, the use of perfluorocarbon for treating premature babies whose lungs are not fully developed and adults who have lung damage occurring from inflammation or swelling of the lungs, aspiration of food or vomit, smoke inhalation or lung burns. Perfluorocarbon is a liquid chemical normally used to cool electronic equipment and carries more dissolved oxygen than air. Liquid breathing works better in distressed lungs than in normal lungs. The linings of normal lungs are coated with surfactant, a natural detergent which reduces the surface tension of water. With reduced surface tension, the surface of a liquid contracts, minimizing its surface area. This allows the lungs to fill up with air and not collapse. Perfluorocarbon has a very low surface tension and can penetrate even into the smallest cavities of the lung, keeping the lungs inflated and allowing oxygen exchange with the blood. Treatment of other premature babies with perfluorocarbon will occur, including those that have not been treated with conventional therapies, which in some cases can actually lead to damage of the lungs.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1989
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Frustrated with Fortran? Bored by Basic? Try OOP!
Article Abstract:
Object-orient programming is replacing procedural programming in C or Fortran for scientific computing. This new approach, using hybrid languages such as C++, divides a problem into separately programmable objects, making programs easier to write, understand, debug and modify.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1993
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