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  • 核酸

    An arm with medical IV lines attached for cancer treatment.

    How do we treat cancer with chemistry?
    ::我们如何用化学治疗癌症?

    Cancer treatment is a complex and challenging effort. Cancer cells grow without the usual controls that act on normal cells. One approach to treating cancer is to alter the structure of the DNA in order to slow down or stop the growth of the abnormal cells. Compounds that structurally resemble the normal building blocks of DNA have been shown to be very effective in stopping some forms of cancer from spreading throughout the body.
    ::癌症治疗是一项复杂而具有挑战性的努力。癌症细胞在正常细胞上没有通常的控制作用。治疗癌症的一种方法是改变DNA的结构,以减缓或阻止异常细胞的生长。 结构上类似于正常DNA结构的化合物已证明在阻止某些形式的癌症在身体上扩散方面非常有效。

    Nucleic Acids
    ::核酸

    The Swiss biochemist Friedrich Miescher first discovered nitrogen-containing compounds in the nuclei of cells in 1869. The term nucleic acid was used to describe these molecules because of their discovery within the cell nucleus and because of the presence of phosphate groups and their relationship to phosphoric . A nucleic acid is a large biopolymer consisting of many nucleotides . The two primary nucleic acids which are found in cells are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is the carrier of genetic information and is ultimately responsible for how cells produce in order to carry out all the functions necessary for life. RNA is a related molecule that is involved in the mechanism by which the information stored in DNA is eventually converted into protein molecules.
    ::1869年,瑞士生物化学家Friedrich Miescher首次在细胞核心中发现了含氮化合物。核酸一词用于描述这些分子,原因是在细胞核中发现了这些分子,还因为存在磷酸化合物及其与磷酸的关系。核酸是一种由许多核糖核酸组成的大型生物聚合物。在细胞中发现的两种主要的核酸是脱氧核糖核酸(DNA)和核糖核酸(RNA)。DNA是遗传信息的载体,最终负责细胞如何生产,以发挥生命所需的所有功能。核酸是一种相关的分子,它涉及DNA中储存的信息最终转化为蛋白分子的机制。

    The basic components of nucleic acids are nucleotides. A nucleotide is a molecule that contains a five-carbon sugar, a phosphate group, and a nitrogen containing . The five-carbon sugar is either ribose, in the case of RNA, or deoxyribose, in the case of DNA. The only difference between the two molecules is the presence of a hydroxyl group attached to one member of the carbon ring in RNA. In DNA, that same carbon is attached only to a hydrogen atom (see Figure ). Note that in drawing the structure of organic molecules, the single hydrogen atoms are not shown in the structure but are understood to be attached at each carbon point unless another molecule is shown.
    ::核酸的基本成分是核糖。核酸是一种含有五碳糖、磷酸组和氮的分子。在RNA的情况下,五碳糖不是核糖,在DNA的情况下,是脱氧核糖。两种分子之间的唯一区别是,在RNA中,碳环的某一成员有一个附属的氢氧基组。在DNA中,同样的碳只附在氢原子上(见图 )。注意,在绘制有机分子的结构时,结构中没有显示单一氢原子,但被理解为附在每个碳点,除非显示另一个分子。

    Chemical structures of ribose and deoxyribose sugars, components of RNA and DNA.

    The sugars ribose and deoxyribose are components of RNA and DNA respectively.
    ::糖和脱氧核糖核糖核酸分别是RNA和DNA的组成部分。

    The nucleotides form the backbone of RNA and DNA. Each nucleotide consists of a base, a pentose (either ribose or deoxyribose) and phosphate groups (see Figure ). Three of the bases in RNA and DNA are identical (adenine, cytosine, and guanine). Thymine is found in DNA while uracil is found in RNA.
    ::核糖核酸是RNA和DNA的骨干。每一种核酸都包括一个基底、一个钢管(肋骨或脱氧核糖核酸)和磷酸酯组(见图 ) 。 RNA的3个基底和DNA是相同的(九、细胞素和guanine)。在DNA中发现了甲状腺,而在RNA中发现了聚氨酯。

    Chemical structure of nucleotides showing ribose, deoxyribose, bases, and phosphate groups.

    Nucleotides
    ::核分子

     

     

    Review
    ::回顾

    1. What is a nucleic acid?
      ::什么是核酸?
    2. What is a nucleotide?
      ::什么是核核酸?
    3. Which pentose is in DNA and which is in RNA?
      ::DNA中是什么纹身? RNA中是什么纹身?