What I'm going to show you are the astonishing molecular machines that create the living fabric of your body. Now molecules are really, really tiny. And by tiny, I mean really. They're smaller than a wavelength of light, so we have no way to directly observe them. But through science, we do have a fairly good idea of what's going on down at the molecular scale. So what we can do is actually tell you about the molecules, but we don't really have a direct way of showing you the molecules.
我要展示给大家的 是创造了你们身体活组织的 惊人的分子机器 分子实在是很小 说到小呢, 我的意思是真小 它们比光的波长还小, 所以,我们无法直接观察它们 但是,通过科学,我们有一个很好的概念 分子比例是怎么回事 我们能做到真实地告诉你分子的情况, 但我们不能有一个直接的方法把分子展示给你们
One way around this is to draw pictures. And this idea is actually nothing new. Scientists have always created pictures as part of their thinking and discovery process. They draw pictures of what they're observing with their eyes, through technology like telescopes and microscopes, and also what they're thinking about in their minds. I picked two well-known examples, because they're very well-known for expressing science through art.
有一种方法就是画图 实际上这已不是个新方法 科学家们总是在创造图片 作为他们思考和发现过程的一部分 他们借助望远镜和显微镜之类的技术, 以及他们大脑思考的 画出他们所观察到的 我举两个众所周知的例子, 因为他们以通过艺术来表达科学而著名
And I start with Galileo, who used the world's first telescope to look at the Moon. And he transformed our understanding of the Moon. The perception in the 17th century was the Moon was a perfect heavenly sphere. But what Galileo saw was a rocky, barren world, which he expressed through his watercolor painting.
我先从伽利略开始 伽利略用过世界上第一台望远镜 来看月亮 他改变了我们对月亮的理解 17世纪的感知 月亮是个完美的天球 可是,伽利略所看到的是坚硬的,贫瘠的世界, 他通过他的水彩画表达了出来
Another scientist with very big ideas, the superstar of biology is Charles Darwin. And with this famous entry in his notebook, he begins in the top left-hand corner with, "I think," and then sketches out the first tree of life, which is his perception of how all the species, all living things on Earth are connected through evolutionary history -- the origin of species through natural selection and divergence from an ancestral population.
另一位的科学家有一个很大的想法, 他就是生物学界的超级明星-查尔斯·达尔文 在他的笔记里,那著名的开始语, 他从左上角开始写道:“我认为,” 接着呢,画出了第一棵生命树, 那就是他的见解 地球上所有的物种及生物, 如何通过进化的历史而连接起来 物种的起源来自物竞天择 并分歧于一个祖先群体
Even as a scientist, I used to go to lectures by molecular biologists and find them completely incomprehensible, with all the fancy technical language and jargon that they would use in describing their work, until I encountered the artworks of David Goodsell, who is a molecular biologist at the Scripps Institute. And his pictures -- everything's accurate and it's all to scale. And his work illuminated for me what the molecular world inside us is like.
即使作为一名科学家, 我曾参加过分子生物学家们的演讲 发现完全无法理解, 他们使用所有时髦的技术语言和行话 来描述他们的作品, 知道我遇到大卫 古德塞尔的艺术作品, 他是斯克里普斯研究所的分子生物学家 他的图画, 样样都精确,并且都按比例 他的作品对我释明 我们内在的分子世界是什么样
So this is a transection through blood. In the top left-hand corner, you've got this yellow-green area. The yellow-green area is the fluid of blood, which is mostly water, but it's also antibodies, sugars, hormones, that kind of thing. And the red region is a slice into a red blood cell. And those red molecules are hemoglobin. They are actually red; that's what gives blood its color. And hemoglobin acts as a molecular sponge to soak up the oxygen in your lungs and then carry it to other parts of the body.
这是通过血液的一个横断面 在左上角,你看到这个黄绿色的区域 这个黄绿区血液的流体,大部分是水分, 但它也是抗体,糖分, 和激素类的东西 这个红色区是一个红血球的切片 这些红分子是血红蛋白 它们实际就是红色,也就是血液的颜色 血红蛋白像是一个分子海绵 在你的肺里面浸透氧气 再带到身体的其他部位
I was very much inspired by this image many years ago, and I wondered whether we could use computer graphics to represent the molecular world. What would it look like? And that's how I really began. So let's begin.
很多年前,我就很被这个图像所激励, 我就想是否能够使用电脑绘图 来描绘分子世界 它会是个什么样子呢? 就这样我就开始了。现在让我们来看, 这是传统的DNA的双螺旋结构,
This is DNA in its classic double helix form. And it's from X-ray crystallography, so it's an accurate model of DNA. If we unwind the double helix and unzip the two strands, you see these things that look like teeth. Those are the letters of genetic code, the 25,000 genes you've got written in your DNA. This is what they typically talk about -- the genetic code -- this is what they're talking about. But I want to talk about a different aspect of DNA science, and that is the physical nature of DNA. It's these two strands that run in opposite directions for reasons I can't go into right now. But they physically run in opposite directions, which creates a number of complications for your living cells, as you're about to see, most particularly when DNA is being copied.
它来自X射线晶体学, 所以它是一个精确的DNA模型 如果我们把双螺旋展开,把两股拉开, 你们看到它们像牙齿一样 这些就是遗传密码的字母, 在你的DNA上有25,000个基因 这就是他们通常谈论的 -- 遗传密码--大家都这样讲的 我想从不同的角度来谈论DNA科学, 那是DNA的物理性质 这两条线走向不同的方向 我现在先不讲什么原因 它们实际上就是在走向不同的方向, 这就给你们的活细胞制作了大量的混乱, 你会看到, 大多数特别是在DNA复制过程中
And so what I'm about to show you is an accurate representation of the actual DNA replication machine that's occurring right now inside your body, at least 2002 biology. So DNA's entering the production line from the left-hand side, and it hits this collection, these miniature biochemical machines, that are pulling apart the DNA strand and making an exact copy. So DNA comes in and hits this blue, doughnut-shaped structure and it's ripped apart into its two strands. One strand can be copied directly, and you can see these things spooling off to the bottom there. But things aren't so simple for the other strand because it must be copied backwards. So it's thrown out repeatedly in these loops and copied one section at a time, creating two new DNA molecules.
我就要给你们看的是 是一个精确的描述 有关DNA在你身体内部的实际复制, 至少是2002的生物学 DNA从左手边进入生产线, 撞倒这一堆小型的生化机器, 这些生化机器把DNA线拉开,重新复制 DNA进来 碰到这个蓝色的,圆圈状的结构 把两条线扯开 一条线可以直接复制, 你能看到这些放在底部 但另一条线就没有这么简单 因为它要反向复制 它要反复在这些圈里被推出 一次复制一段, 创造两个新的DNA分子
Now you have billions of this machine right now working away inside you, copying your DNA with exquisite fidelity. It's an accurate representation, and it's pretty much at the correct speed for what is occurring inside you. I've left out error correction and a bunch of other things.
现在你有成千上亿的机器 此时此刻就在你里面工作, 忠实细致地复制着你的DNA 这是个很精确的描述, 它的速度和你体内发生的正在进行的一样 我没提一些更正和其它的
(Laughter)
这是几年前的作品
This was work from a number of years ago-- Thank you.
谢谢! 这个是几年前的作品,
(Applause)
This is work from a number of years ago, but what I'll show you next is updated science, it's updated technology. So again, we begin with DNA. And it's jiggling and wiggling there because of the surrounding soup of molecules, which I've stripped away so you can see something. DNA is about two nanometers across, which is really quite tiny. But in each one of your cells, each strand of DNA is about 30 to 40 million nanometers long. So to keep the DNA organized and regulate access to the genetic code, it's wrapped around these purple proteins -- or I've labeled them purple here. It's packaged up and bundled up. All this field of view is a single strand of DNA. This huge package of DNA is called a chromosome. And we'll come back to chromosomes in a minute.
接下来我要给你们看的是最新的科学,最新的技术 我们再次从DNA开始 因为周围被分子包围,它就不停摇摆扭动, 我揭开了所以你们看得到 DNA大约有两个纳米宽, 真的是非常小 在你的每一个细胞里, 每条DNA大约是3至4千万纳米长 为了保持DNA有组织有规律地到达遗传密码, 它是被这些紫色的蛋白质包着-- 这是我是用了紫色 它打好包,打好捆 这里看到的是单条的DNA 这一大包的DNA叫做染色体 我们过会再回来讲染色体
We're pulling out, we're zooming out, out through a nuclear pore, which is the gateway to this compartment that holds all the DNA, called the nucleus. All of this field of view is about a semester's worth of biology, and I've got seven minutes, So we're not going to be able to do that today? No, I'm being told, "No."
我们拉出来,拉远缩小, 通过核膜孔拉出来, 核膜孔是通往储存DNA包厢的通道 称为细胞核 这里所看到的 够上一个学期的生物课,我把它压缩成7分钟 所以今天我们能不能讲那么细呢? 不能的,我被告知,不能的
This is the way a living cell looks down a light microscope. And it's been filmed under time-lapse, which is why you can see it moving. The nuclear envelope breaks down. These sausage-shaped things are the chromosomes, and we'll focus on them. They go through this very striking motion that is focused on these little red spots. When the cell feels it's ready to go, it rips apart the chromosome. One set of DNA goes to one side, the other side gets the other set of DNA -- identical copies of DNA. And then the cell splits down the middle. And again, you have billions of cells undergoing this process right now inside of you.
这里是在光学显微镜下看到的活细胞 因为是採用慢速摄影,所以你们能看到它在动 核膜打开了 这些形状像香肠的是染色体,我们集中讲一下他们 它们通过非常明显的运动 集中在这些小红点上 当细胞准备好了, 它就脱离染色体 一组DNA去这一边, 另一组DNA就去另一边 DNA的复制一模一样 接下来,细胞在中间分裂 同样,你有成千上亿的细胞 此时此刻在你体内正在做这个工序
Now we're going to rewind and just focus on the chromosomes, and look at its structure and describe it. So again, here we are at that equator moment. The chromosomes line up. And if we isolate just one chromosome, we're going to pull it out and have a look at its structure. So this is one of the biggest molecular structures that you have, at least as far as we've discovered so far inside of us. So this is a single chromosome. And you have two strands of DNA in each chromosome. One is bundled up into one sausage. The other strand is bundled up into the other sausage.
我们再回来看染色体 看看它的结构来讲述一下 我们现在是赤道时刻 染色体们排着队 如果我们分出一条染色体, 我们把它拿出来看看它的结构 这是你拥有的最大分子结构之一, 至少是至今我们发现的我们体内的 这是个单条染色体 每条染色体有两条DNA 一条卷起来进到一条香肠里 另一条卷起来进到另一条香肠里
These things that look like whiskers that are sticking out from either side are the dynamic scaffolding of the cell. They're called microtubules, that name's not important. But we're going to focus on the region labeled red here -- and it's the interface between the dynamic scaffolding and the chromosomes. It is obviously central to the movement of the chromosomes. We have no idea, really, as to how it's achieving that movement.
这些像胡须的东西从另一头伸出来 它们是细胞的动态支架 他们称作微管。名字并不重要 我们要集中在这个红色区域,我把它标成红色 这是个接口 介于动态支架和染色体之间 很显然,它是染色体运动的中枢 我们也搞不懂它到底是怎么运动的
We've been studying this thing they call the kinetochore for over a hundred years with intense study, and we're still just beginning to discover what it's about. It is made up of about 200 different types of proteins, thousands of proteins in total. It is a signal broadcasting system. It broadcasts through chemical signals, telling the rest of the cell when it's ready, when it feels that everything is aligned and ready to go for the separation of the chromosomes. It is able to couple onto the growing and shrinking microtubules.
我们一直在研究一种叫动力球的东西 认真研究了上百年, 我们发现它仍处在初级阶段 它由大约200种不同的蛋白质组成, 总共有上千种蛋白质 它是一个信号传播系统 它通过化学信号传播 告诉其它的细胞它准备好了, 当它觉得事情都准备好了 为了染色体的分裂 它能够把成长的和缩小的微管连接起来
It's involved with the growing of the microtubules, and it's able to transiently couple onto them. It's also an attention-sensing system. It's able to feel when the cell is ready, when the chromosome is correctly positioned. It's turning green here because it feels that everything is just right. And you'll see, there's this one little last bit that's still remaining red. And it's walked away down the microtubules. That is the signal broadcasting system sending out the stop signal. And it's walked away -- I mean, it's that mechanical. It's molecular clockwork.
它也参与微管的成长, 它能暂时连接它们 它也是个能感觉注意力的系统 它能感觉到什么时候细胞准备好了, 什么时候染色体位置正确 这里变成绿色 因为它感觉样样都对 你会看到,这里有一点点 还是红色 它在微管下面走开了 这是信号传播系统发出停止的信号 它走开了,我的意思是,它是机械的 分子式钟表装置
This is how you work at the molecular scale. So with a little bit of molecular eye candy,
这就是在分子比例层的工作 有点分子式的华而不实,
(Laughter)
我们还有驱动蛋白,是这些橙色的
we've got kinesins, the orange ones. They're little molecular courier molecules walking one way. And here are the dynein, they're carrying that broadcasting system. And they've got their long legs so they can step around obstacles and so on. So again, this is all derived accurately from the science. The problem is we can't show it to you any other way.
它们是分子的信差,单向行走 这里是动力蛋白。它们携带者传播系统 它们有长长的腿,能跨越障碍物 同样地,从科学的角度来说 所有这些都很精确 问题是我们不能用别的方法展示给你们看
Exploring at the frontier of science, at the frontier of human understanding, is mind-blowing. Discovering this stuff is certainly a pleasurable incentive to work in science. But most medical researchers -- discovering the stuff is simply steps along the path to the big goals, which are to eradicate disease, to eliminate the suffering and the misery that disease causes and to lift people out of poverty.
用人类的领悟力的前沿, 来探索科学的前沿, 太令人兴奋了 去发现这些东西 确实是在科学领域工作的令人愉快的奖励 但,大多数的医学研究者们, 发现这种东西 只是通往远大目标的简单步骤, 那就是根除疾病, 减少疾病造成的痛苦和不幸 带人脱离贫困。
Thank you.
谢谢!
(Applause)
(掌声)