7.1.1 DNA_视频在线视频

这是DNA结构和染色体结构 DNA叫什么？
This is the structure of DNA and chromosome.What is DNA called?

脱氧核糖核酸 它的结构是什么样的呢？
What is the structure of deoxyribonucleic acid?

染色体是双螺旋结构 DNA是染色体的组成部分 它到底是一个什么样的结构呢？
Chromosome is a double helix structure and DNA is a part of chromosome.What kind of structure is it?

首先我们看看DNA结构的重要性
First of all,let's look at the importance of DNA structure

毋庸置疑 它对遗传进化都很重要
It's undoubtedly very important for genetic evolution

我们上一代的信息要传到下一代 通过DNA的复制
The information of our generation will be transmitted to the next generation through DNA replication

所以这些DNA的结构要能复制的 要复制才能够遗传
so the structure of these DNA can be inherited only if it can be replicated

我们了解DNA的结构也是像蛋白质那样去了解它的功能
We understand the structure of DNA as well as the function of protein

结构和功能是相互匹配的
The structure and function of DNA match each other

什么样的结构就决定有什么样的功能
What kind of structure determines what kind of function it has

我们了解它的结构 就是为了更好的去了解它的功能
We understand its structure in order to better understand its function

这些DNA和染色体的结构是怎么知道的呢？
How do we know the structure of these DNA and chromosomes?

在过去有一门学问叫作X-射线晶体学
In the past,there was a science called X-ray crystallography

给这个晶体打上射线以后呢它就会 这个X-射线就会探测到信息
When the crystal was irradiated,it would detect the information

然后通过计算机图形还原到分子结构
and then restore it to the molecular structure through computer graphics

这些探测器上有这些结构 要通过图像来模拟 形成一个模型
These detectors have these structures,which need to be simulated by images to form a model

所以我们看到的双螺旋结构 分子结构 都是计算机模拟出来的一个结构
so the double helix structure and molecular structure we see are all computer simulated structures

那么为什么这个叫作脱氧核糖核酸呢？
So why is this called deoxyribonucleic acid?

这里有一个氧的话 就是氧核糖核酸 氧没有了 我们就叫脱氧核糖
If there is one oxygen,that is,oxyribonucleic acid.If there is no oxygen,we call it deoxyribose

这三个部分就构成了核苷酸 那么这三个部分 这个大分子
These three parts make up nucleotides,and then these three parts,the macromolecule

再相互连接就形成了DNA 所以核苷酸是构成DNA的主要分子结构
connect to each other to form DNA.So nucleotides are the main molecular structure of DNA

刚刚我们说核苷酸有碱基有磷酸还有脱氧核糖
We just said that nucleotides have bases,phosphoric acid and deoxyribose

那么它这个碱基是其中的一个 碱基有五种
so this base is one of them.There are five bases

这里主要介绍四种含氮碱基 A叫腺嘌呤
Here we mainly introduce four nitrogenous bases.A is called adenine

分子结构是两个含氮的结构 这是核苷酸的一个主要成分
The molecular structure is two nitrogenous structures,which is one of the main components of nucleotides

第二种是鸟嘌呤 可以用G表示
The second is guanine,which can be expressed in G

前面这个腺嘌呤用A表示
and the previous adenine in A

第三个是胞嘧啶 以C来代表
The third one is cytosine,represented by C

最后一个是胸腺嘧啶 叫T
and the last one is thymine,called T

这四种含氮碱基也就决定了我们前面这些核苷酸的特性
These four nitrogen-containing bases also determine the characteristics of these nucleotides in front of us

这些含有不同碱基的核苷酸连在一块 就构成了DNA的结构
These nucleotides with different basic group are linked together to form the structure of DNA

我们看核糖和脱氧核糖 脱氧核糖就是DNA 核糖就是RNA
Let's look at ribose and deoxyribose.Deoxyribose is DNA and ribose is RNA

唯一区别就是有一个脱氧
The only difference is that there is one deoxygenation

那么我们根据氧原子顺时针的顺序 这是1号-5号
Then we follow the clockwise sequence of oxygen atoms,which is Number 1-5

核糖也是一样的
The same is true for ribose

这个编号对我们后面了解它的性质和DNA复制的时候很重要
This number is very important for us to understand its nature and DNA replication later

下面我们看DNA的结构 到底是长什么样的呢？
Now let's look at the structure of DNA.What exactly does it look like?

一级结构就是多聚核苷酸长链
The primary structure is the long chain of polynucleotides