文档介绍：Chapter 11 The Chemistry of life (生命的化学)
Prebiotic chemistry(生命前化学)
Chemistry and the Control of insect pests (害虫防治与化学)
The chemistry of photosynthesis(光合作用化学)
The catalysts of life--enzymes(生命的催化剂—酶)
The role of chemistry in molecular biology and biotechnology(化学在分子生物学和生物技术中的作用)
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Prebiotic chemistry
Prebiotic chemistry is concerned with how life could have arisen on earth, if indeed it arose by the spontaneous(自发) development(进化) of primitive chemistry into living chemistry. Understanding how this process might have happened could also help us understand what conditions would be needed for the development of life on other s.
Some problems in this field have already been solved. For example, it has been shown that important chemical building blocks(板块) of current living systems--such as amino acids, sugars, ponents(组分) of RNA and DNA--can be formed spontaneously from chemicals likely to have been present on the primitive earth. What is needed to promote chemical reactions is the ultraviolet(紫外) light from the sun, electric discharges from lighting, and other conditions that must have been present in early times on this .
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A particular problem in this field has recently been solved. Currently living creatures use enzymes(酶) to achieve the biochemical synthesis(合成) of RNA, and RNA to direct the synthesis of enzymes, which are proteins. How could such a cycle get started spontaneously, if ponent is needed to make the other? Thomas Cech and Sydney Altman found--and received the Nobel Prize in Chemistry in 1989 for their discovery--that some RNA molecules can catalyze(催化) reactions just as enzymes do, although not as well. This finding suggests that the earliest life could have involved RNA acting both as the information molecule--the role it now plays--and also as the catalyst to turn that information into the production of new molecules.
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According to this idea, there was an RNA world of life that came first. It was replaced