发布时间 : 星期一 文章生物专业英语中英文对照（蒋悟生）第2版 Bioengineering English更新完毕开始阅读
Bioengineering English
Glossary
one-gene-one-enzyme hypothesis 一基因一酶假说
The hypothesis that a large class of gene exist in which each gene controls the synthesis or activity of but a single enzyme. Since enzymes and other proteins whose syntheses are controlled by more than one gene are now known, this hypothesis has been replaced by the one-gene-one polypeptide hypothesis. one-gene-one-polypeptide hypothesis一基因一多肽假说
The hypothesis that a large class of genes exist
purine 嘌呤
in which each gene controls the synthesis of a
One of a group of nitrogenous bases whose
single polypeptide. The polypeptide may
parent compound has the formula shown.
function independently or as a subunit of a
The two most abundant purines are adenine
more complex protein.
and guanine, which are constituents of nucleic
adenine 腺嘌呤
A purine base that is an essential constituent of
pyrimidine 嘧啶
the nucleic acids and also of such coenzymes as NAD and FAD. guanine 鸟嘌呤
A heterocyclic organic compound, C4N4N2 the fundamental form of pyrimidine bases. Some of these bases are constituents of nucleic
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A double-ring nitrogenous base molecule in DNA and RNA. It is the complementary base of cytosine. cytosine胞嘧啶
A single-ring nitrogenous base molecule in DNA and RNA. It is complementary to guanine.
thymine 胸腺嘧啶
A single-ring nitrogenous base molecule of DNA but not RNA. It is complementary to adenine.
acids and coenzymes.
Bioengineering English
acid.
nucleoside 核苷
A purine or pyrimidine base attached to ribose or deoxyribose. The nucleosides commonly found in DNA and RNA are: cytidine, cytosine deoxyriboside, thymidine, uridine, adenosine, adenine
deoxyriboside,
guanosine,
and
DNA double helix 双螺旋 The
three-dimensional
structure
of
doublestranded DNA.
semiconservative replication 半保留复制 The method of replication of DNA in which the molecule divides longitudinally, each half being conserved and acting as a template for the formation of a new strand. replication fork 复制叉
A point at which the two strands of a DNA double helix are unwound and separated during replication.
Okazaki fragment 冈琦片断
A short sequence of DNA that is the primary product of DNA polymerase during DNA replication.
polymerase DNA 聚合酶
An enzyme that brings new DNA triphosphate nucleotides into position for bonding on another DNA molecule.
guanine deoxyriboside. Note that thymidine is a deoxyriboside and cytidine, uridine, adenosine,and guanosine are ribosides. X-ray diffraction X射线衍射
A technique for determining the arrangement of atoms in a crystalline substance by analysing the diffraction patterns produced when a narrow beam of X-rays is passed through the substance. X-ray diffraction has contributed to the elucidation of structure of many biological molecules, including some important
macromolecules,
e.g.,
DNA,
haemoglobin, myoglobin.
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Bioengineering English
Lesson Six
The Origin and Diversity of Life
A Home for Life: Formation of the Solar System and Planet Earth
The story of life's origins begins with the formation of the earth. The sequence of events that gave rise to our planet began, in turn, with the cosmic explosion physicists call the Big Bang. The sun at the center of our solar system condensed from a cloud of primordial matter roughly 5 billion years ago; the planets, including the earth, condensed about 4.6 billion years ago. The earth is composed of a number of layers: a solid crust, a semisolid mantle, and a largely molten (liquid) core that has a solid center. Basic physical features of Earth that may have made the emergence of life possible include the planet's size, temperature, composition, and distance from the sun. The major current hypothesis holds that life arose spontaneously on the early earth by means of chemical evolution from nonliving substances.
生命起源于地球的形成。大爆炸是我们行星形成的开始。太阳在50亿年前生成，位于太阳系中心，行星，包括地球，在46亿年前生成。地球由多层组成：坚硬的地壳，半流体的地幔，一个很大的溶解中心中存在一个坚实的中心。地球的基本特征使生命起源成为可能，包括行星的大小，温度，组成以及离太阳的距离。当前主要假设认为，由非生命的化学物质进化过程自发产生了生命。
The Emergence of life: Organic and Biological Molecules on a Primitive Planet
Evidence for prelife stages of chemical organization comes from laboratory experiments that try to duplicate the physical environment and chemical resources of the early earth. These experiments, including the pioneering work of Miller and Urey, have successfully produced
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Bioengineering English
organic monomers including amino acids, simple sugars, and nucleic acid bases. The probable next step toward life was the spontaneous linking of such monomers into polymers such as proteinoids and nuclei acids. Current research suggests that likely sites for this polymerization were clay or rock surfaces.
通过创造出地球早期的自然条件和化学资源条件，科学家在实验室中已经获得了化学有机体生命前阶段的证据。这些实验包括米勒等早期所做工作，成功地产出了有机单体，包括氨基酸，单糖，核酸碱基。这些单体自发的连接成多聚体，如类蛋白和核酸，使进入生命状态成为可能。这些聚合作用可能发生在泥土或岩石表面。
Researchers have found that, when energy is available to a system, they can generate three kinds of organic molecular aggregates. The Russian Aleksandr Oparin obtained polymer-rich droplets, called coacervates from solutions of polymers. Sidney Fox generated proteinoid microspheres from mixtures of amino acids and water. A third laboratory structure is the liposome, a spherical lipid bilayer that forms from phospholipids. A structure similar to one or more of these aggregates may have been the precursor of true cells.
当一个系统获得能量时，可能发生3种有机分子的聚集。从多聚物的溶液中俄国科学家获得了富含小液滴的多聚物，即凝聚物。从氨基酸和水的混合液中Fox获得了类蛋白微球体。实验室第三个结构物质是脂质体，即由磷脂形成的球形脂双层结构。
Further steps in the appearance of cells on the earth included the development of RNA and DNA as biological information molecules. Evidence suggests that RNA, which can form spontaneously under conditions mimicking those of the early earth, was the first informational molecule. The discovery of RNA ribozymes-RNA that can act as an enzymelike catalyst suggests that such catalytic RNA also could have assembled new RNAs from early nucleotides. Certain catalytic RNAs can also carry out sexlike exchanges of pieces of RNA.
RNA可能是地球早期形成的第一个贮藏信息的物质。在实验室模拟早期地球自然条件下其可自发形成。核酶的发现说明它可以催化早期核酸形成新的RNA。对于RNA物种而言，
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