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  • 核心 - 高级

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    Where does the DNA live?
    ::DNA住在哪里?

    The answer depends on if the is prokaryotic or eukaryotic. The main difference between the two types of cells is the presence of a nucleus. In eukaryotic cells , lives in the nucleus.
    ::答案取决于是蛋白质还是尿道。 两种细胞的主要区别是核的存在。 在蛋白质细胞中, 生活在核中 。

    The Nucleus
    ::核心

    The nucleus is a membrane-enclosed found in most eukaryotic cells. The nucleus is the largest organelle in the cell and contains most of the cell's genetic information ( also contain DNA, called mitochondrial DNA, but it makes up just a small percentage of the cell's overall DNA content). The genetic information, which contains the information for the structure and function of the organism , is found encoded in DNA in the form of genes . A gene is a short segment of DNA that contains information to encode an molecule or a strand. DNA in the nucleus is organized in long linear strands that are attached to different proteins. These proteins help the DNA to coil up for better storage in the nucleus. Think how a string gets tightly coiled up if you twist one end while holding the other end. These long strands of coiled-up DNA and proteins are called . Each chromosome contains many genes. Humans have about 20,000 to 22,000 genes scattered among 23 chromosomes.
    ::核核是在大多数尿道细胞中发现的膜封闭核。 核核是细胞中最大的有机体, 并包含细胞的大部分遗传信息( 也包括DNA, 称为线粒体DNA, 但它只占细胞全部DNA含量的一小部分 ) 。 基因信息包含生物体结构和功能的信息, 以基因的形式在DNA中被编码。 基因是DNA的短片, 含有将分子或线条编码的信息。 核中的DNA组织在与不同蛋白质相连的长线条中。 这些蛋白质有助于DNA粘合起来, 以更好地储存在核中。 想想如果在保持另一端时扭动一端, 一根绳子是如何被紧紧凝固起来的。 这些粘结的DNA和蛋白的长片被调用为DNA。 每个染色体包含许多基因。 人类有大约20,000到22,000个基因分布在23个染色体中。

    Essentially, the nucleus is the control center of the cell. The function of the nucleus is to maintain the integrity of the genes and to control the activities of the cell by regulating . Gene expression is the process by which the information in a gene is "decoded" by various cell molecules to produce a functional gene product, such as a protein molecule or an RNA molecule. Gene expression is a highly regulated process, ensuring RNA and proteins are only produced when necessary.
    ::基本来说,核心是细胞的控制中心。核心的功能是保持基因的完整性,通过调节控制细胞的活动。基因表达方式是由各种细胞分子“解码”基因中的信息,以产生功能性基因产品,如蛋白分子或RNA分子。基因表达方式是一个高度规范的过程,确保只有在必要的时候才能产生RNA和蛋白质。

    The degree of DNA coiling determines whether the chromosome strands are short and thick or long and thin. Between cell divisions, the DNA in chromosomes is more loosely coiled and forms long thin strands called chromatin . DNA is in this uncoiled form during the majority of the , making the DNA available to the proteins involved in DNA replication and . Before the cell divides, the chromatin coils up more tightly and form chromosomes. Only chromosomes stain clearly enough to be seen under a . The word chromosome comes from the Greek word chroma (color), and soma (body) due to its ability to be stained strongly by dyes.
    ::DNA粘结的程度决定了染色体系是短的、厚的还是长的和薄的。 在细胞分裂之间,染色体中的DNA比较松散,形成称为染色体的长细的细细的线条。DNA在大部分情况下是未腐蚀的。DNA在大部分情况下是未腐化的形式,使DNA复制所涉及的蛋白可以被使用。在细胞分裂之前,染色体圈更加紧紧,形成染色体。只有染色体的污点才明显可见于染色体下。染色体的字词来自希腊的染色体(颜色)和索马(体),因为它能够被染色体强烈地染色。

    Nuclear Envelope
    ::核信封

    The nuclear envelope is a double membrane of the nucleus that encloses the genetic material . It separates the contents of the nucleus from the cytoplasm . The nuclear envelope is made of two phospholipid bilayers, an inner membrane and an outer membrane. The outer membrane is continuous with the rough endoplasmic reticulum . Many tiny holes called nuclear pores are found in the nuclear envelope. These nuclear pores help to regulate the exchange of materials (such as RNA and proteins) between the nucleus and the cytoplasm.
    ::核封套是囊括基因材料的核核核的双膜,将核核核的内装物与细胞托盘分开。核封套由两个磷素双层组成,一个内膜,另一个外膜。外膜与粗外皮内皮的内膜相接。在核封套中发现许多小洞,称为核孔。这些核孔有助于调节核核核与细胞托盘之间的材料交换(如RNA和蛋白质)。

    Nucleolus
    ::核核核列

    The nucleus of many cells also contains an organelle called a nucleolus , shown in Figure . The nucleolus is mainly involved in the assembly of . Ribosomes are organelles made of protein and ribosomal RNA (rRNA), and they build cellular proteins in the cytoplasm. The function of the rRNA is to provide a way of decoding the genetic messages within another type of RNA, called mRNA for messenger RNA , into amino acids . After being made in the nucleolus, ribosomes are exported to the cytoplasm where they direct .
    ::许多细胞的核心也包含一个有机体,称为核核素,如图所示。核素主要与核素组装有关。Ribocomes是蛋白质和核素RNA(rRNA)的有机体,在细胞图层中制造细胞蛋白。RRNA的功能是提供一种方法,将遗传信息解密到另一种RNA,即信使RNA的MRNA,变成氨基酸。在核素中制成后,核素被导导导出到细胞图层。

    lesson content

    The eukaryotic cell nucleus. Visible in this diagram are the ribosome-studded double membranes of the nuclear envelope, the DNA (as chromatin), and the nucleolus. Within the cell nucleus is a viscous liquid called nucleoplasm, similar to the cytoplasm found outside the nucleus. The chromatin (which is normally invisible), is visible in this figure only to show that it is spread out throughout the nucleus.
    ::eukaryatic 细胞核。 此图中可见核包、 DNA( 作为铬) 和核核糖核的核糖核。 在细胞核中, 一种叫做核核糖核的粘结液, 类似于核外发现的细胞托巴利姆。 铬( 通常为隐形的) , 可见于此图中, 仅显示其散布于核中。

      

     

     

    Summary
    ::摘要

    • The nucleus is a membrane-enclosed organelle, found in most eukaryotic cells, which stores the genetic material (DNA).
      ::核核是一种薄膜封闭的器官,在大多数含有遗传材料(DNA)的表单细胞中发现。
    • The nucleus is surrounded by a double lipid bilayer, the nuclear envelope, which is embedded with nuclear pores.
      ::核核心周围是双脂双层, 核封套, 里面装有核孔。
    • The nucleolus is inside the nucleus, and is where ribosomes are made.
      ::核核糖核在核核中, 核糖核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核,核核核核核核核核核核核核核核核核核核核核核核核核核核,核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核,核核核核核核核核核核核核核核核核核核核核核核核核核核,核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核,核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核,核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核核

    Review
    ::回顾

    1. What is the role of the nucleus of a eukaryotic cell?
      ::欧元细胞核心的作用是什么?
    2. Describe the nuclear envelope.
      ::描述一下核子信封
    3. What are nuclear pores?
      ::什么是核子孔?
    4. What is the role of the nucleolus?
      ::核核糖核糖核核酸的作用是什么?