Section outline

  • General

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  • 笔译 笔译

    What will you learn
    ::你会学到什么

    • How are made from through translation
      ::如何通过翻译作出
    • The structure of tRNA and its role in translation
      ::TRNA的结构及其在翻译方面的作用

    A heart shape filled with the word 'welcome' in various languages.

    RNA to proteins. How?
    ::RNA对蛋白质的RNA,怎么做?

    You must translate. To go from one language to another. Spanish to English, French to German, or nucleotides to amino acids . Which type is the translation of molecular biology ? Obviously, the type of translating discussed here translates from the language of nucleotides to the language of amino acids.
    ::您必须翻译。 要从一种语言翻译成另一种语言, 西班牙语到英语, 法语到德语, 核糖酸到氨基酸。 哪一种是分子生物学的翻译? 显然, 这里讨论的翻译类型可以从核糖酸的语言翻译成氨基酸的语言 。

    Translation
    ::笔译 笔译

    Translation is the second part of the central dogma of molecular biology : RNA → Protein . It is the process in which the in mRNA is read, one codon at a time, to make a protein.  After mRNA leaves the , it moves to a , which consists of rRNA and proteins. The ribosome reads the sequence of codons in mRNA. Molecules of tRNA bring amino acids to the ribosome in the correct sequence.
    ::翻译是分子生物学核心教条的第二部分:RNA Protein。 这是读取 mRNA 中的 mRNA 的过程, 一次一个codon 来制造蛋白质。 在 mRNA 离开后, 它会移动到由 RRNA 和 蛋白质组成的一个 。 肋骨可以读取 mRNA 中的codon 序列 。 tRNA 的 Molecules 将氨基酸以正确的顺序带入肋骨 。

    Translation of the codons in mRNA to a chain of amino acids occurs at a ribosome. Notice the growing amino acid chain attached to the tRNAs and ribosome. Find the different types of RNA in the diagram. What are their roles in translation?
    Illustration of tRNA based on image from David S. Goodsell and the RCSB PDB under a license. Original image: https://pdb101.rcsb.org/motm/15.

    To understand the role of tRNA, you need to know more about its structure. Each tRNA molecule has an anticodon for the amino acid it carries. An anticodon is a sequence of 3 bases, and is complementary to the codon for an amino acid, as seen in the Figure . For example, the amino acid lysine has the codon AAG, so the anticodon is UUC. Therefore, lysine would be carried by a tRNA molecule with the anticodon UUC. Wherever the codon AAG appears in mRNA, a UUC anticodon on a tRNA temporarily binds to the codon. While bound to the mRNA, the tRNA gives up its amino acid. Bonds form between adjacent amino acids as they are brought one by one to the ribosome, forming a  polypeptide chain. The chain of amino acids keeps growing until a stop codon is reached.
    ::要了解 tRNA 的作用, 您需要了解它的结构。 每个 tRNA 分子都有对应其携带的氨酸的抗codon。 抗codon 是3个基数的序列, 与氨酸的codon是互补的, 如图所示。 例如, 氨酸碱有Codon AAG, 所以抗codon 是UUUC。 因此, 氨酸将由抗codon UUUC 的tRNA 分子携带。 只要Codon AAAG出现在 mRNA 中, 一个tRNA 的UC 抗codon 暂时粘合到codon 。 在与 mRNA 捆绑在一起的同时, tRNA 也放弃其氨酸 。 相邻的氨酸的邦体形式, 当它们被一个一个一个带到核糖体, 形成一个聚苯酯链时, 氨酸链会继续生长, 直到达到停止 codondon。

    TRNA structure with anticodon and amino acid attachment, illustrating role in translation.
    The tRNA structure (A) is a very important aspect in its role. Though the molecule folds into a 3-leaf clover structure (B), notice the anticodon arm in the lower segment of the molecule, with the amino acid attached at the opposite end of the molecule (acceptor stem). It is the anticodon that determines which codon in the mRNA the tRNA will bind to.

    After a polypeptide chain is synthesized, it may undergo additional processes. For example, it may assume a folded shape due to interactions among its amino acids. It may also bind with other polypeptides or with different types of molecules, such as or . Many proteins travel to the to be modified for the ir specific function . 
    ::在合成了聚石化物链之后,它可能会经历额外的过程。例如,它可能因其氨基酸之间的相互作用而形成折叠形状,它也可能与其他聚石化物或不同种类的分子结合,例如,或。许多蛋白质会经过修改以适应其特定功能。

    Can you place the steps in the process of translation in the correct order?
    ::您能否按照正确的顺序排列翻译过程中的步骤?

     

     

    Summary
    ::摘要

    • Translation is the RNA → Protein part of the central dogma.
      ::翻译是中央教条的RNA 蛋白质部分。
    • Translation occurs at a ribosome.
      ::翻译发生在排卵器上。
    • During translation, a protein is synthesized using the codons in mRNA as a guide.
      ::在翻译过程中,蛋白质会以 mRNA 中的codon 做为指南,合成蛋白质。
    • All three types of RNA play a role in translation.
      ::所有这三类RNA在翻译中都发挥了作用。

    Review
    ::回顾

    1. Outline the steps of translation.
      ::概要说明翻译步骤。
    2. Discuss the structure of a tRNA molecule, and its role in translation.
      ::讨论tRNA分子的结构及其在翻译中的作用。
    3. How are transcription and translation related to the central dogma of molecular biology?
      ::分子生物学中心教条的抄录和翻译如何相关?