ADM-201 dump PMP dumps pdf SSCP exam materials CBAP exam sample questions

DNA: 一本关于你的书 – 译学馆
未登录,请登录后再发表信息
最新评论 (0)
播放视频

DNA: 一本关于你的书

DNA: The book of you - Joe Hanson

每个人都是这样来到世上的
Every human being starts out the same way:
两个细胞,分别来自父母
two cells, one from each parent,
找到彼此变成一个
found each other and became one.
这个细胞复制自己
And that one cell reproduced itself,
分裂,分裂,再分裂
dividing, dividing and dividing
直到他们多达十万亿
until there were 10 trillion of them.
你知道一个人的身体里的细胞
Do you realize there’s more cells in one person’s body
比银河里的星星还要多吗?
than there are stars in the Milky Way?
但这十万亿细胞不只是在那聚成一堆
But those 10 trillion cells aren’t just sitting there in a big pile.
这将会是一个相当无聊的人
That would make for a pretty boring human being!
那么鼻子是鼻子说的是什么呢?
So what is it that says a nose is a nose,
那脚趾是脚趾呢
and toes is toes?
这是骨头又说的是什么呢?
What is it that says this is bone
这是大脑呢
and this is brain
这是心脏呢
and this is heart
这是你喉咙后面那个小东西呢
and this is that little thing in the back of your throat
你从来不记得它的名字?
you can never remember the name of?
构成现在的你和将来的你的所有一切
Everything you are or ever will be made of
作为一本小的说明书开始
starts as a tiny book of instructions
在每一个细胞里中发现
found in each and every cell.
每次你的身体想做些什么
Every time your body wants to make something,
它可以追溯到说明书
it goes back to the instruction book,
它会检查并重组
looks it up and puts it together.
那么单个细胞是如何掌握这么多信息的呢?
So how does one cell hold all that information?
让我们变小吧
Let’s get small.
我是说,变小吧——比一个针头还小
I mean, really small — smaller than the tip of a sewing needle.
下面我们在单细胞里进行一次旅行
Then we can take a journey inside a single cell
去发现这本造汝之书,
to find out what makes up the book of you,
你的染色体。
your genome.
我们首先看到的就是完整的染色体,你的所有DNA,
The first thing we see is that the whole genome, all your DNA,
被包裹在一间微小的隔间中,
is contained inside its own tiny compartment,
它叫细胞核。
called the nucleus.
如果我们将一个细胞中所有的 DNA 展开成一条单螺旋线,
If we stretched out all the DNA in this one cell into a single thread,
它将有3英尺长!
it would be over 3 feet long!
我们不得不将它装好,放进一间
We have to make it fit in a tiny compartment
比它小一百万倍的隔间。
that’s a million times smaller.
我们能将它像圣诞彩灯一样串起来,
We could just bunch it up like Christmas lights,
但会一团糟。
but that could get messy.
我们需要一些支撑体。
We need some organization.
首先,这些长螺旋DNA缠绕在
First, the long thread of DNA wraps around proteins
聚集成珠叫做核小体的蛋白质上,
clustered into little beads called nucleosomes,
会在看起来像一条长珠项链时结束。
which end up looking like a long, beaded necklace.
这条项链包裹在自身的螺旋中,
And that necklace is wrapped up in its own spiral,
像一条老电话线。
like an old telephone cord.
这些项链分层堆积在彼此之上,
And those spirals get layered on top of one another
直到我们得到一个小小的整齐的适合在细胞核内的形状。
until we get a neat little shape that fits inside the nucleus.
瞧!三英尺长的DNA塞进了一个小小 的隔间。
Voilà! Three feet of DNA squeezed into a tiny compartment.
要是我们能雇佣DNA来打包我们的小提箱该多好啊!
If only we could hire DNA to pack our suitcases!
每一个微小的DNA称为一条染色体。
Each tiny mass of DNA is called a chromosome.
造汝之书将有46章,
The book of you would have 46 chapters,
每张对应各自的染色体。
one for each chromosome.
造汝之书有23章来自于你的母亲,
Twenty-three chapters of your book came from your mom,
另外23章来自于你的父亲。
and 23 chapters came from your dad.
其中两章,分别称为“X”和“Y”
Two of those chapters, called ‘X’ and ‘Y,’
决定你是男人,“XY”,
determine if you’re male, ‘XY,’
或女人,“XX”。
or female, ‘XX.’
将它们放在一起,我们会得到
Put them together, and we get
两套几乎相同,但略有不同的23章。
two almost identical but slightly different sets of 23 chapters.
微小的变异造成每个人都不一样,
The tiny variations are what makes each person different.
估计所有章节总共
It’s estimated that all the chapters together
拥有大约20000个个性化指令,称为基因
hold about 20,000 individual instructions, called genes.
将这些20000个指令写出来,
Written out, all those 20,000 instructions
会有3千万个字母那么长!
are 30 million letters long!
如果有人一秒写一个字母,
If someone were writing one letter per second,
书写它们一次将会花费他们几乎一年的时间。
it would take them almost an entire year to write it once.
事实证明,我们的基因组的书
It turns out that our genome book is much, much longer
比区区3千万个字母长得多——
than just those 30 million letters —
几乎100倍长!
almost 100 times longer!
额外的书页是干啥的呢?
What are all those extra pages for?
每一页的指令有几页无意义的废话插入,
Well, each page of instructions has a few pages of nonsense inserted
在我们结束一些有用的事之前必须拿出。
that have to be taken out before we end up with something useful.
扔掉的部分,我们称为内含子(非编码基因)。
The parts we throw out, we call introns.
保留的指令,我们称为外显子(编码基因)。
The instructions we keep, we call exons.
我们在每个基因中有成千上百页。
We can also have hundreds of pages in between each gene.
有些多余的页是被
Some of these excess pages were inserted
讨厌的小感染插入我们祖先的基因中。
by nasty little infections in our ancestors,
但是它们中的一些实际上是有帮助的
but some of them are actually helpful.
他们保护每一章的最后不被损坏,
They protect the ends of each chapter from being damaged,
或者有些帮助我们的细胞找到它们正在寻找的一些特殊的事情。
or some help our cells find a particular thing they’re looking for,
或者给一个细胞信号停止生产。
or give a cell a signal to stop making something.
总之,每一页的指令,
All in all, for every page of instructions,
都几乎有100页的填充。
there’s almost 100 pages of filler.
最终,每个我们的46章
In the end, each of our books’ 46 chapters
长度达到48到250百万个字母。
is between 48 and 250 million letters long.
总长3.2万亿个字母!
That’s 3.2 billion letters total!
为了打印所有的复制体
To type all that copy,
需要超过百年的时间
you’d be at it for over 100 years,
这本书会超过600,000页
and the book would be over 600,000 pages long.
每种细胞携带这本相同的书
Every type of cell carries the same book,
但每个细胞都有一系列书签
but each has a set of bookmarks
用来判断哪一页是它要查看的
that tell it exactly which pages it needs to look up.
所以一个骨骼细胞只读取那组要它成为骨骼的指令
So a bone cell reads only the set of instructions it needs to become bone.
你的大脑细胞
Your brain cells,
它们读取了让它们成为大脑的部分
they read the set that tells them how to become brain.
如果一些细胞突然决定开始阅读其他指令
If some cells suddenly decide to start reading other instructions,
他们可以从一种形式变成另一种
they can actually change from one type to another.
所以你体内每个小细胞延续了一本不可思议的书
So every little cell in your body is holding on to an amazing book,
满是对生活的指令
full of the instructions for life.
你的鼻子读取鼻子的书页
Your nose reads nose pages,
你的脚趾读取脚趾的书页
your toes read toes pages.
而在你喉咙后边的小东西呢
And that little thing in the back of your throat?
它也读取了它的书页
It’s got its own pages, too.
他们在“小舌”下面
They’re under ‘uvula.’

发表评论

译制信息
视频概述
听录译者

收集自网络

翻译译者

收集自网络

审核员

自动通过审核

视频来源

https://www.youtube.com/watch?v=aeAL6xThfL8

相关推荐