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  • General

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  • 病毒特征

    Cartoon virus character with angry expression and exaggerated features.

    This virus looks alive, but is it?
    ::这个病毒看起来是活生生的,是吗?

    Notice the big . He (or she) looks very angry. But actually viruses cannot be a "he" or a "she" - or big either. In fact, viruses are the smallest things. Much smaller than most . We also cannot say that viruses are the smallest living things or organisms , as viruses do not meet the definition of living or of an organism.
    ::注意大的东西。 他(或她)看起来非常生气。 但实际上病毒不能是“他”或“她”或“她”,也不能是大的东西。 事实上,病毒是最小的东西。 比大多数小得多。我们也不能说病毒是最小的生物或生物体,因为病毒不符合生命或生物体的定义。

    Characteristics of Viruses
    ::病毒特征

    Which of the three of life do viruses belong to? None. Why? Viruses are usually considered to be nonliving. Viruses do not meet most of the criteria of life. They are not even made of .
    ::哪个生命中的三个病毒属于哪个病毒? 没有。 为什么? 病毒通常被视为非生物。 病毒不符合大部分生命标准。 它们甚至不是由

    A virus is a sub-microscopic particle that can infect living cells. Viruses are much smaller than prokaryotes, ranging in size from about 20–300 nanometers (nm), though some can be larger. Prokaryotes are typically 0.5–5.0 micrometers (µm) in length. For example, if a virus was about the size of three soccer balls lying side-by-side, then a prokaryote would be about the size of soccer field.
    ::病毒是一种能感染活细胞的亚微微粒子。 病毒比原虫小得多,其体积从20-300纳米左右,尽管有些可能更大。 丙烯酸盐一般长为0.5-5.0微米。 比如,如果病毒的体积与相邻的三颗足球的体积差不多,那么,prokaryote的体积就会与足球场的体积差不多。

    An individual virus is called a virion . It is a tiny particle much smaller than a prokaryotic cell . Because viruses do not consist of cells, they also lack , cytoplasm , , and other cell . Without these structures, they are unable to make or even reproduce on their own. Instead, they must depend on a host cell to synthesize their proteins and to make copies of themselves. Although viruses are not classified as living things, they share two important traits with living things. They have genetic material , and they can evolve. This is why the of viruses has been controversial. It calls into question just what it means to be alive. What do you think? How would you classify viruses?
    ::个人病毒被称为病毒。 它是一个小微粒子, 大大小于一个蛋白质细胞。 因为病毒不是细胞, 它们也缺乏细胞, 细胞, 和其他细胞。 没有这些结构, 它们就无法自己制造甚至繁殖。 相反, 它们必须依靠宿主细胞合成蛋白质和复制自己。 尽管病毒没有被归类为生物, 它们与生物有两种重要的特征。 它们有遗传物质, 并且它们可以演化。 这就是为什么病毒是有争议的。 它使人质疑生存意味着什么。 你觉得呢? 你会如何将病毒分类呢?

    The study of viruses is known as virology and people who study viruses are known as virologists . Viruses infect and live inside the cells of living organisms. When viruses infect the cells of their host, they may cause disease. For example, viruses cause AIDS (Acquired immune deficiency syndrome), influenza (flu), chicken pox, and the common cold. Therapy is sometimes difficult for . Antibiotics have no effect on viruses and only a few antiviral drugs are available for some diseases. One of the best ways to prevent viral diseases is with a vaccine , which produces . But vaccines are available for only a few diseases.
    ::病毒研究被称为病毒学,研究病毒的人被称为病毒学家,病毒感染并生活在活生物体细胞中,病毒感染其宿主细胞时,它们可能造成疾病,例如病毒导致艾滋病(后天免疫机能丧失综合症)、流感(流感)、禽流感(流感)、天花和普通寒冷。治疗有时对治疗很困难。抗生素对病毒没有影响,某些疾病只有少量抗病毒药物。预防病毒疾病的最佳方法之一是疫苗,疫苗产生。但疫苗只能用于少数疾病。

    Mimivirus, shown in the Figure , is the largest known virus, with a diameter of 400 nm. Protein filaments measuring 100 nm stick out from the surface of the virus, which increases the diameter of the virus to about 600 nm. This is bigger than a small bacterial cell. The virus appears hexagonal under an electron ; the viral shape is icosahedral (having 20 faces or sides).
    ::图中显示的米米病毒是已知的最大病毒,直径400纳米。 蛋白丝从病毒表面直径为100纳米,将病毒直径增加至约600纳米。 这比一个小细菌细胞大。 病毒在电子下出现六角;病毒形状为象形(有20张面或两面)。

    The mimivirus structure, indicating its size, shape, and genetic composition.

    The largest known virus, called mimivirus, is so large that scientists first mistook it for a bacterium. It was first discovered in amoeba, in 1992, and was identified as a virus in 2003. Scientists believe that mimivirus may cause certain types of pneumonia in humans. The core contains DNA, with the majority of the DNA in genes, and only 10% DNA of unknown function ("junk" DNA).
    ::最大的已知病毒叫做咪咪病毒,其规模之大,科学家首先误认为是细菌。 它于1992年在阿莫埃巴首次发现,2003年被确定为病毒。 科学家认为咪咪病毒可能导致人类某些类型的肺炎。 核心含有DNA,大部分DNA都存在于基因中,只有10%的DNA具有未知功能(“垃圾”DNA ) 。

    Replication
    ::复制复制

    Viruses can replicate only by infecting a host cell. They cannot reproduce on their own. Viruses are not cells; they are a strand of genetic material within a protective protein coat called a capsid . They infect a wide variety of organisms, including both eukaryotes and prokaryotes. Once inside the cell, they use the cell’s ATP , ribosomes, , and other cellular parts to replicate.
    ::病毒只能通过感染宿主细胞复制才能复制。 病毒不是细胞;病毒是保护性蛋白外皮中的基因材料,叫做卡皮。 它们感染了各种各样的生物,包括eukaryotes和prokaryotes。 一旦进入细胞,它们就会使用细胞的ATP、Ripsosomes和其他细胞部件复制。

    Habitats
    ::生境和生境

    Viruses can be found almost anywhere there is life, including living within prokaryotes. A phage is a virus that infects prokaryotes. Phages are estimated to be the most widely distributed and diverse entities in the , even more numerous than prokaryotic organisms. Phages can be found everywhere their hosts are found, such as in soil , in the intestine of , or seawater. Up to 10 9 virions have been found in a milliliter of seawater, and up to 70 percent of may be infected by phages. They are also found in drinking and in some foods, including fermented vegetables and meats, where they control the growth of bacteria.
    ::几乎在任何地方都能找到病毒,包括生活在长内。长是一种感染长的病毒。据估计,在这种病毒中,灯光是分布最广泛和种类最多的实体,甚至比蛋白质生物还多。其宿主到处都能找到灯光,如土壤、肠子或海水中。在一毫升海水中发现了多达109种病毒,其中多达70%可能感染了phage。它们还存在于饮用水和一些食物中,包括发酵蔬菜和肉类中,它们控制着细菌的生长。

    Summary
    ::摘要

    • Viruses are tiny particles, smaller than prokaryotic cells.
      ::病毒是微小的粒子,比蛋白质细胞小。
    • Viruses are not cells and cannot replicate without help, but they have nucleic acids and can evolve.
      ::病毒不是细胞,不能在没有帮助的情况下复制,但它们有核酸,可以进化。

    Review
    ::回顾

    1. What is a virus?
      ::什么是病毒?
    2. What are the two main components of a virus?
      ::病毒的两个主要组成部分是什么?
    3. How do viruses differ from living things? How are they similar to living things?
      ::病毒与生物有什么不同?它们与生物有什么相似之处?
    4. Briefly describe how viruses depend on host cells.
      ::简要说明病毒如何依赖主机细胞。
    5. What two characteristics of life are evident in viruses?
      ::在病毒中,生命的哪些两个特征是显而易见的?
    6. What is a phage?
      ::什么是法眼?