蛋白质合成 - 高级

Is it always DNA to RNA to proteins?
::它总是DNA到RNA到蛋白质?

The central dogma of molecular biology . Coined by Francis Crick. And in his own words, "I called this idea the central dogma, for two reasons, I suspect. I had already used the obvious word hypothesis in the sequence hypothesis, and in addition I wanted to suggest that this new assumption was more central and more powerful."
::分子生物学的核心教条。由Francis Crick附着。用他自己的话说,“我称这个思想为中心教条,原因有二:我怀疑。我已经在序列假设中使用了明显的假说词,此外,我还想暗示这个新假设更中枢、更有力。”

DNA → RNA → Protein
::DNA RNA 蛋白质

If never leaves the , and are in the cytoplasm , how does “DNA makes makes protein” actually happen? The two processes necessary to make a from the information in DNA are and . Transcription, which happens in the nucleus, uses the DNA sequence to make an RNA molecule. The RNA then leaves the nucleus and goes to the cytoplasm where translation occurs on a ribosome and produces a protein. 
::如果“DNA制造蛋白质”从来没有离开过,并且还在细胞顶层中,那么“DNA制造蛋白质”是如何实际发生的呢?从DNA信息中产生一个信息的两个过程是 和 。在核中发生的转基因,使用DNA序列来制造RNA分子。RNA然后离开核,然后转到细胞顶层,在核素上进行翻译并产生蛋白质。

The central dogma of molecular biology was first described by Francis Crick, who with James Watson first described the structure of DNA, in 1958 and re-stated in a Nature paper published in 1970. He stated that, "The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred back from protein to either protein or ." This central dogma explains the molecular transfer of sequence information. It was simplified by Marshall Nirenberg, the scientist who cracked the , who said, "DNA makes RNA makes protein."
::分子生物学的中心教条最初由Francis Crick描述,他与James Watson一起于1958年首次描述DNA结构,并在1970年出版的《自然》论文中重述。他说,“分子生物学的中心教条涉及按顺序信息的详细残存转移。它说这种信息不能从蛋白质转移到蛋白质或蛋白质。”这个中心教条解释了序列信息的分子转移。它被Marshall Nirenberg简化了,那个科学家说,“DNA使RNA产生蛋白质。”

The central dogma of molecular biology describes the fundamental process that makes us all different. We all essentially have the same genes and proteins. Though we have the same genes, we have different of those genes. And though we may have the same proteins, such as we have the protein collagen found in , many of our proteins are slightly different and thus work slightly differently. If all our proteins acted the same way, we would all be exactly the same. Our proteins are slightly different because we have different alleles. Those alleles are what makes us unique. They are our particle version of the genetic instructions. It is those small difference in the DNA sequence of different alleles that is translated into small differences in the mRNA molecules. And those differences in the mRNAs are then translated into proteins. And those small differences in the order of amino acids in proteins are enough to make us all different.
::分子生物学的核心教条描述了使我们所有人都不同的基本过程。 我们基本上都有相同的基因和蛋白质。 虽然我们有相同的基因,但我们有不同的基因。 虽然我们可能有相同的蛋白质,例如我们发现有蛋白质的科朗基因,但我们的许多蛋白质略有不同,因此效果也略有不同。如果我们所有的蛋白都以同样的方式行事,我们都会完全相同。我们的蛋白质之所以略有不同,是因为我们有不同的异灵。这些异灵使我们有不同的基因和蛋白质。它们是我们基因指令的粒子版本。它们是不同基因的粒子序列中的微小差异,被转化成微小的 mRNA分子的DNA序列。这些差异随后被转化成蛋白质。而蛋白质中氨酸的微小差异足以使我们都不同。

Transfer of Sequence Information
::序列信息传输

The polymers that comprise DNA, RNA and amino acids are linear polymers. Each monomer (a nucleotide or amino acid) is connected to, at most, two other monomers. The sequence of their monomers encodes genetic information. The transfers of information described by the central dogma based on the order of monomers that make this genetic information. The polymer's (DNA or RNA) sequence is used as a template for the construction of another polymer with a sequence that is entirely dependent on the original polymer's sequence. The DNA sequence is used to encode RNA, and the RNA sequence is used to encode protein. Are those the only transfers of genetic information?
::由DNA、RNA和氨基酸组成的聚合物是线性聚合物。每个单体(核酸或氨基酸)最多与另外两个单体相连。它们的单体序列编码基因信息。中央教条根据生成这种基因信息的单体顺序描述的信息的转移。聚合物序列(DNA或RNA)序列被用作构建另一个聚合物的模板,其序列完全取决于原聚合物序列。DNA序列用于编码RNA,而RNA序列用于编码蛋白。这些是遗传信息的唯一转移吗?

With three biopolymers (DNA, RNA, and protein), there could be as many as nine potential types of transfers. The central dogma classes these into three groups of three
::有三种生物聚合物(DNA、RNA和蛋白质),可能会有多达九种潜在的转移类型。

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1. three general transfers,
   ::3项一般转让,
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2. three special transfers,
   ::3项特别转让,
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3. three unknown transfers.
   ::三次不明转移。

The three general transfers are believed to occur normally in most . These describe the normal flow of biological information. DNA is replicated, DNA is transcribed into RNA, and RNA is translated into protein. The three special transfers are known to occur under special conditions, such as with some . The three unknown transfers are not believed to occur.
::据认为,三种一般转移通常通常发生在大多数情况下。这些都描述了生物信息的正常流动。DNA被复制,DNA被转录到RNA,RNA被转化成蛋白质。三种特殊转移已知在特殊条件下发生,例如一些特殊条件下发生。据认为,三种未知转移不会发生。

Reverse Transcription
::逆反转转

Reverse transcription is the transfer of information from RNA to DNA. The is the reverse of normal transcription. Reverse transcription occurs in retroviruses , such as , the virus that causes AIDS. Retroviruses are RNA viruses that are duplicated in a host cell by using reverse transcriptase to produce DNA from its RNA genome .
::反转转录入是信息从RNA向DNA的传输,这是正常转录的反转录入。反转录入反转录入反转录入反转录入病毒,例如导致艾滋病的病毒。反转录入病毒是RNA病毒,通过使用反转转录入酶从RNA基因组中产生DNA,在主机细胞中复制RNA病毒。

Reverse transcription also occurs with retrotransposons and during telomere synthesis in eukaryotes . Retrotransposons are self-replicating segments of eukaryotic genomes that use reverse transcriptase to move from one position in the genome to another via a RNA intermediate. A telomere is a region of repetitive noncoding nucleotide sequences at each end of a . These sequences protect the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Each time DNA is replicated, small segments of DNA from the ends of the chromosome is lost. Telomerase is a reverse transcriptase that uses an RNA intermediate to elongate the 3' end of DNA strands in the telomere regions after each replication cycle.
::逆转转录入器中也出现逆转转录入器,在eukaryotes 中还会出现反转录入器。反转录入器是eukaryots 基因组中自复制部分,使用反转转录入器从基因组中的一个位置通过RNA中间体从一个位置移到另一个位置。一个tolomere是一个在a的每个端都重复出现非编码核糖核酸序列的区域。这些序列可以保护染色体的末端不会变质,或不会与相邻的染色体相融合。每次复制DNA时,都会失去染色体端的少量DNA。Telomerase是一种逆转录入器,在每次复制周期后,使用RNA中间体将调出DNA线的3端拉长。

RNA Replication
::RNA 复制

RNA replication is the copying of one RNA to another. Many RNA viruses copy their RNA using RNA replication. RNA-dependent RNA polymerases are the enzymes specific for this process, as opposed DNA-dependent RNA polymerase , which catalyzes the transcription of RNA from a DNA template. RNA-dependent RNA polymerase is also known as RNA replicase. These enzymes are found in many eukaryotic cells , where they are involved in RNA silencing. RNA silencing refers to mechanisms of gene silencing, in which the expression of one or more genes is downregulated or entirely suppressed by the binding of an antisense RNA molecule. An antisense RNA molecule is a single-stranded RNA that is complementary to a mRNA strand transcribed within a cell. These two RNAs bind to each other and prevent translation. RNA interference is a form of gene silencing.
::RNA复制一个RNA复制到另一个RNA。许多RNA病毒复制了他们的RNA复制。RNA依赖RNA的聚合物是这个过程特有的酶,而不是DNA依赖RNA的聚合物,它们从DNA模板中催化RNA的转录。RNA依赖RNA的聚合物也称为RNA复制。这些酶存在于许多电子细胞中,它们参与RNA的静默。RNA的静默是指基因静默机制,其中一种或多种基因的表达方式被一个抗感应RNA分子的捆绑压低或完全抑制。一种抗感应RNA分子是一种单一的RNA,它与细胞中转录的 mRNA线是相辅相成的。这两个RNA相互捆绑在一起,防止翻译。RNA的干扰是一种基因静默。RNA的干扰是一种基因抑制形式。

Summary
::摘要

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• “DNA makes RNA makes protein” is the central dogma of molecular biology.
  ::“DNA使RNA制造蛋白质”是分子生物学的中心教条。
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• Other transfers of genetic information include RNA replication and reverse transcription.
  ::其他遗传信息转让包括RNA复制和反转转录入。

Review
::回顾

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1. What is meant by “DNA → RNA → Protein?”
   ::“DNA ’ RNA ’ Protein?” 指的是什么?
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2. What is a biopolymer? What are the three types of biopolymers? Make a table illustrating the nine potential types of transfers.
   ::生物聚合物是什么?三种生物聚合物是什么?
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3. Describe reverse transcription.
   ::描述反向转录。
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4. Define RNA silencing.
   ::定义 RNA 沉默。