2012-2013学年 专业音乐 chapter1 lesson3 page12-14 [gene]
cells:the Basic Unit of Life Monday, November 19, 2012
细胞生命活动的基本单位
THE MOLECULES of life,the chemical reactions that they undergo are not randomly dispersed in living organism.( 生命的分子，化学反应，他们接受不是随机分散在活的有机体。) ON the contrary they are elaborately organized and compartmentalized.( 反之，他们精心地组织和分割) the fundamental unit of this organization is the cell.( 基本单位的组织细胞)
All living things are composed of cells.( 所有的生物都是由细胞组成的) cells of different plants and animals and of different organs within a single plant or animal present a bewildering variety of sizes shapes colors and structures but all have certain features in common,( 细胞不同的植物和动物的不同器官在一个单一的植物或动物提出一个扑朔迷离的各种尺寸形状颜色和结构，但都有一些共同的特点
) each cell is surrounded by a plasma membrane and has a variety of subcellular structures known ai organelles immersed in the cytoplasm(fig.1) 每个细胞是由质膜包围并具有多种亚细胞结构称艾沉浸在细胞质中细胞器（图）
The plasma membrane is made of lipid and protein and is a living functional part of the cell extremely important in regulating its contents. 血浆膜是由脂质和蛋白质，是一种生活的部分功能，细胞极重要的规范的内容。 All food entering the cell and all waste products or secretions leaving it must pass throuth this membrane. 所有食物进入细胞，所有废物或分泌物离开它必须经过这个膜。 Nearly all plant cells (but not most animal cells) have a thick cell wall made of cellulose outside of the plasma membrane . 几乎所有的植物细胞
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2012-2013学年 专业音乐 chapter1 lesson3 page12-14 [gene]
（但不是大多数动物细胞）有一个厚厚的细胞壁由纤维素以外的质膜。This cell wall is nonliving produced ai a secretion of the living protoplasm. 这是生命的细胞壁产生人工智能的原生质分泌。The cell wall is pieced in many places by tiny holes through which the protoplasm of one cell connects with that of the adjacent cells. 细胞壁是拼凑在许多地方的微小孔，一个细胞的细胞质连接与邻近的细胞 through these perforations materials can pass from one cell to another. 通过这些穿孔材料可以从一个细胞转移到另一个 These tough firm cell walls provide support for the plant body. 这些公司的细胞壁提供支持植物体.
The organelles are like divisions of a factory ,each with its own specifically assigned task. 细胞分裂是像工厂，每一个都有自己的具体分配任务 the largest and most conspicuous organelle within the cells of most organisms is the nucleus. 最大和最明显的器官的细胞内大多数生物体是原子核.the cells of bacteria,however,lack not only well-defined nuclei but most of the other organelles as well. 细胞中的细菌，然而，不仅缺乏明确的细胞核，但大多数其他器官以及. The entire nucleus is surrounded by a distinctive double-membrane nuclear envelope,which helps maintain a chemical environment winthin the nucleus different from thai in the surrounding cytoplasm. 整个核的周围是一个独特的双膜核膜，这有助于保持化学环境在核周围的细胞质不同，泰国 inside the membrane,there are two distinct types of structure:long,threadlike bodies called chromosome and generally oval bodies called nucleoli. 膜内，有2种不同类型的结构：长，丝状体称为染色体一般椭圆体称为核仁。 They both embedded in a mass of amorphous material known as nucleoplasm. 他们都嵌入在一个大规模的非晶材料称为核质。Beacause the chromosome is composed of complex of DNA and protein,the nucleus is an
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2012-2013学年 专业音乐 chapter1 lesson3 page12-14 [gene]
Important center of controlling of the cell,directing cellular activity and containming the hereditary factors(gens) responsible for the traits of an organism. 因为染色体是由复杂的核酸和蛋白质，核是一个重要的中心控制的细胞，将细胞活性和遏制有遗传因素（氏族）负责性状有机体。
The role of the nucleus can be studied by removing it and observing the consequences. 作用的核研究可以通过删除它和观测的后果。By using microneedles,the nucleus of the single-celled animal amoeba can be removed. 通过使用微针，细胞核的单细胞动物阿米巴可以被删除.after the operation,the cell continuous to live and move,but it cannot grow and die after a few days. 手术后，细胞不断的生活和行动，但它不能成长和死亡后几天. A series of experiments demonstrated the importance of the nucleus is controlling the growth of the cell was performed bu scientists ,the results show that nucleus is necessary for the metabolic process that regulates growth and cell reproduction. 一系列的实验证明的重要性，核心是控制细胞的生长进行卜科学家，结果表明，核是必要的代谢过程，调节细胞生长和繁殖
Mitochondria,the main powerhoushes of eucaryotic cells,are responsible for supplying energy to other paris of the cell on demand. 线粒体，主要powerhoushes真核细胞，负责提供能源的其他巴黎的细胞上的需求 like the nucleus,each mitochondrion is bounded by a double membrane:the outer membrane is smooth while the inner one has many inwardly directed folds called cristae. 如核，每个线粒体是由双层膜：外膜光滑，内有许多向内褶皱称为嵴.
Another important apparatus in cells are endoplasmic reticulum(ER) 另一个重要的设备在
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2012-2013学年 专业音乐 chapter1 lesson3 page12-14 [gene]
细胞内质网（急诊室）.although varies greatly in appearance in different cells,the endoplasmic reticulum is always act as the foundation for synthesizing molecules such ai protein or lipid. 虽然差别很大，出现在不同的细胞中，内质网始终是作为基础的合成分子例如蛋白质或脂质。 Most endoplasmic reticulum is membrane is lined on its outer surface with ribosomes,small protein synthesizing organelles built from rRNA derived from the nucleolus. 大多数内质网是膜内衬的外表面与核糖体蛋白质合成的细胞器，小从基因来源于核仁.in this case,the endoplasmic reticulum is spoken of ai rough ER,and no ribosome lined is described as smooth ER. 在这种情况下，内质网是人工智能的粗糙内质网，并没有被描述为光面内质网核糖体内衬
Golgi bodies,another type of living lnclusion are found in the cytoplasm of all cells except mature sperm and red blood cells,and believe to be necessary for store,package and transport secretory products,are distinguished from mitochondria by the fact that they stain with neuteral red instead of Janus green. 高尔基体，另一种生活包含被发现在细胞质中的所有细胞除成熟精子和红血细胞，并认为有必要储存，包装和运输分泌的产品，有别于线粒体的事实，他们染色，中性胶代替贾纳斯绿色红色.an investigator centrifugalized cells in a high speed centrifuge and showed that mitochondria are heavier,and Golgi bodies lighter than the rest of protoplasm. 调查员离心分离细胞在高速离心机和表明，线粒体和高尔基体较重，比其余的原生质.
Most cells,both plant and animal,are too small to be seen with the naked eye. 大多数细胞，植物和动物，太小，用肉眼看到的.their diameters range from about 1 micron to 100 microns and a speck of 100 microns in diamenter is about at the lower limits of visibility. 其直径范围从大约1微米到100微米和100微米的直径大约是在能见度下限。 A few
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2012-2013学年 专业音乐 chapter1 lesson3 page12-14 [gene]
species of amoebas are a millimeter or two in diameter;some single-celled plants such as acetabularia may be a centimeter or more long. 一些物种的变形虫是一毫米或双直径；一些单细胞植物如伞藻可能是厘米或更久。 Some of the largest single cells are the egg cell of fishes and birds. 一些最大的单细胞的卵细胞的鱼类和鸟类.the egg cell of a large bird may be several centimeters in diameter. 卵细胞。一个大的鸟可能是几厘米直径.only the yolk of the egg is the true egg cell;the white of the egg is a noncellular material secreted by the hen is oviduct. 只有蛋黄的鸡蛋是真正的卵细胞；白色的蛋是一种非物质分泌的母鸡输卵管。
In addition to these living elements,cytoplasm may contain many other organelles,such as vacuoles,plastid and centrosome,etc. 除了这些生活元素，细胞质含有许多其他器官，如液泡，质体和中心体，等. Each has its indispensable function to the cells. 各有其不可或缺的功能的细胞
The limit to the size of a cell is set by the physical fact as a sphere increases in size. 限制大小的细胞是由物理事实作为一个球的大小增加.the volume increases only as the cube of the radius. 容积增大，只有作为立方体的半径 since cellular metabolism requires oxygen and nutrient that can enter only through the cell,above which the surface area is to supply the metabolic activities of the enclosed protoplasm. 由于细胞代谢需要氧气和养分，可只有通过输入单元，其上方的表面积是供应的代谢活动的封闭的原生质.the actual size of the limit will depend on the shape of the cell and the rate ai which metabolism occurs. 实际大小的限制将取决于形状的细胞和代谢发生率人工智能.when the limit is reached,the cell must either stop growing or divide. 当达到极限，细胞必须停止增长或分
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