I'd like you to ask yourself, what do you feel when you hear the words "organic chemistry?" What comes to mind? There is a course offered at nearly every university, and it's called Organic Chemistry, and it is a grueling, heavy introduction to the subject, a flood of content that overwhelms students, and you have to ace it if you want to become a doctor or a dentist or a veterinarian. And that is why so many students perceive this science like this ... as an obstacle in their path, and they fear it and they hate it and they call it a weed-out course. What a cruel thing for a subject to do to young people, weed them out. And this perception spread beyond college campuses long ago. There is a universal anxiety about these two words.
我想请各位问问自己, 当你听到 “有机化学” 这个词时, 你会有什么感觉? 你会想到什么呢? 几乎每所大学都提供这样一门课程, 叫做 “有机化学” , 这门课程是十分复杂、 累人的有机化学入门, 一大堆内容使学生们叫苦不迭, 如果你想成为医生、牙医或者兽医, 你将不得不学好这门课程, 那就是为什么很多学生 都是这样看待这个学科的...... 前途上的障碍。 他们害怕它,讨厌它, 把它叫做 “劝退课”。 这门科目对年轻人多么残忍—— 把他们淘汰。 而这个认知在很久以前 就传播到了大学校园之外。 围绕这四个字产生了 一种普遍的焦虑。
I happen to love this science, and I think this position in which we have placed it is inexcusable. It's not good for science, and it's not good for society, and I don't think it has to be this way. And I don't mean that this class should be easier. It shouldn't. But your perception of these two words should not be defined by the experiences of premed students who frankly are going through a very anxious time of their lives. So I'm here today because I believe that a basic knowledge of organic chemistry is valuable, and I think that it can be made accessible to everybody, and I'd like to prove that to you today. Would you let me try?
我恰巧喜爱这门学科, 我认为我们对它如此定位 是不可原谅的。 这对社会和科学都很不好, 而我认为它不必如此。 我并不是说课程内容应该更简单, 它不应被简化。 但是,你对这四个字的感知 不应该由医学预科生的体验来定义, 说实话,他们正在经历 人生中非常焦虑的时期。 所以,我今天在这里演讲, 是因为我相信 有机化学的基础知识是很有价值的, 而且我觉得它可以普及至每一个人, 今天,我就想证明给大家看。 你愿意让我试一下吗?
Audience: Yeah!
观众: 好!
Jakob Magolan: All right, let's go for it.
雅各布:好,让我们上吧。
(Laughter)
(笑声)
Here I have one of these overpriced EpiPens. Inside it is a drug called epinephrine. Epinephrine can restart the beat of my heart, or it could stop a life-threatening allergic reaction. An injection of this right here will do it. It would be like turning the ignition switch in my body's fight-or-flight machinery. My heart rate, my blood pressure would go up so blood could rush to my muscles. My pupils would dilate. I would feel a wave of strength. Epinephrine has been the difference between life and death for many people. This is like a little miracle that you can hold in your fingers.
这是一支昂贵的肾上腺素注射笔。 里面装有一种叫做肾上腺素的药。 肾上腺素能使心脏重新起搏, 也能阻止致命的过敏反应。 只需在这里扎一下就能生效。 它就像是启动了 我体内战斗或逃跑 反应机制的点火开关。 我的心率和血压会上升, 让血液得以涌入肌肉。 我的瞳孔会扩张, 我将感到一股力量。 对很多人来说, 肾上腺素能决定生死。 它就像一个可以握在指间的小小奇迹。
Here is the chemical structure of epinephrine. This is what organic chemistry looks like. It looks like lines and letters ... No meaning to most people. I'd like to show you what I see when I look at that picture. I see a physical object that has depth and rotating parts, and it's moving. We call this a compound or a molecule, and it is 26 atoms that are stitched together by atomic bonds. The unique arrangement of these atoms gives epinephrine its identity, but nobody has ever actually seen one of these, because they're very small, so we're going to call this an artistic impression, and I want to explain to you how small this is. In here, I have less than half a milligram of it dissolved in water. It's the mass of a grain of sand. The number of epinephrine molecules in here is one quintillion. That's 18 zeroes. That number is hard to visualize. Seven billion of us on this planet? Maybe 400 billion stars in our galaxy? You're not even close. If you wanted to get into the right ballpark, you'd have to imagine every grain of sand on every beach, under all the oceans and lakes, and then shrink them all so they fit in here.
这是肾上腺素的化学结构。 这就是有机化学的样子。 像是一堆线条和字母…… 对很多人来说,没有意义。 我想向大家展示一下 在我眼里这幅图的样子。 我看到了一个实体, 有立体深度和旋转的部件, 它也在转动。 我们把它叫做化合物或者分子, 它有 26 个原子, 由原子键接合在一起。 这些原子的独特排列 决定了肾上腺素的特征, 但从未有人亲眼看到过它们, 因为它们太小了, 所以我们把这个称为一种艺术形象, 我会向你解释它有多小。 在这里,我把不到半毫克的 肾上腺素溶解在水里。 相当于一粒沙子的质量。 这里面的肾上腺素分子的数量 是一百万的三次方。 也就是 18 个零。 这个数字很难想象。 生活在这个星球上的 70 亿人口? 或者说银河系中的 4000 亿颗星星? 差得太远了。 如果想给出一个接近的估计, 你必须得想象 所有海滩、海底和湖底的全部沙子, 然后把它们缩小到 能全部塞进这支试管里。
Epinephrine is so small we will never see it, not through any microscope ever, but we know what it looks like, because it shows itself through some sophisticated machines with fancy names like "nuclear magnetic resonance spectrometers." So visible or not, we know this molecule very well. We know it is made of four different types of atoms, hydrogen, carbon, oxygen and nitrogen. These are the colors we typically use for them. Everything in our universe is made of little spheres that we call atoms. There's about a hundred of these basic ingredients, and they're all made from three smaller particles: protons, neutrons, electrons. We arrange these atoms into this familiar table. We give them each a name and a number. But life as we know it doesn't need all of these, just a smaller subset, just these. And there are four atoms in particular that stand apart from the rest as the main building blocks of life, and they are the same ones that are found in epinephrine: hydrogen, carbon, nitrogen and oxygen. Now what I tell you next is the most important part. When these atoms connect to form molecules, they follow a set of rules. Hydrogen makes one bond, oxygen always makes two, nitrogen makes three and carbon makes four. That's it. HONC -- one, two, three, four. If you can count to four, and you can misspell the word "honk," you're going to remember this for the rest of your lives.
肾上腺素非常小, 小到我们永远无法看见它, 甚至借助显微镜也没用, 但我们知道它长什么样子, 因为一些复杂的仪器能让它 “现形”, 这些仪器的名字都很炫酷, 比如,“核磁共振光谱仪”。 所以,不管能否看见, 我们对这个分子了如指掌。 我们知道它是由 四种不同的原子构成的, 氢、碳、氧和氮。 这些是表示它们时惯用的颜色。 宇宙中的所有事物 都是由这些小球体组成的, 我们称之为原子。 这样的基础成分有约 100 种, 而它们都是由 三种更小的粒子构成的: 质子、中子、电子。 我们把这些原子 放进这个熟悉的元素表中。 我们给每个原子 起了一个名字和号码。 但是我们所知的生命 并不需要所有这些原子, 只需要一个更小的子集, 也就是这些。 而其中又有四个原子尤其与众不同, 它们是生命的主要组成部分, 也是肾上腺素中的四种原子: 氢、碳、氮和氧。 我接下来要讲的是最重要的部分。 当这些原子连接在一起 形成分子的时候, 它们会遵循一些规则。 氢能形成一个化学键, 氧总是形成两个键, 氮形成三个键, 而碳则形成四个键。 就是这样。 HONC —— 1,2,3,4。 如果你能数到四,并能拼错 “honk(摁喇叭;与 honc 同音)”这个词, 那你这辈子都能记住了。
(Laughter)
(笑声)
Now here I have four bowls with these ingredients. We can use these to build molecules. Let's start with epinephrine. Now, these bonds between atoms, they're made of electrons. Atoms use electrons like arms to reach out and hold their neighbors. Two electrons in each bond, like a handshake, and like a handshake, they are not permanent. They can let go of one atom and grab another. That's what we call a chemical reaction, when atoms exchange partners and make new molecules. The backbone of epinephrine is made mostly of carbon atoms, and that's common. Carbon is life's favorite structural building material, because it makes a good number of handshakes with just the right grip strength. That's why we define organic chemistry as the study of carbon molecules.
这里有四碗这些原料。 我们可以用它们来构建分子。 让我们从肾上腺素开始。 这些在原子之间的键是由电子构成的。 原子用电子形成键, 就像伸出手臂拉住隔壁的原子。 每个键中有两个电子,就像是在握手, 当然和握手一样, 它们也不是永恒的。 它们可以放开一个原子,抓住另一个。 我们把这个称为化学反应, 也就是原子交换搭档,产生新的分子。 肾上腺素的骨架大部分由碳原子构成, 这是很普遍的。 碳是生命中最受欢迎的建造材料, 因为它能握好几个手, 且 “握手” 的力度也恰到好处。 这就是为什么我们把有机化学 定义为对碳分子的研究。
Now, if we build the smallest molecules we can think of that follow our rules, they highlight our rules, and they have familiar names: water, ammonia and methane, H20 and NH3 and CH4. The words "hydrogen," "oxygen" and "nitrogen" -- we use the same words to name these three molecules that have two atoms each. They still follow the rules, because they have one, two and three bonds between them. That's why oxygen gets called O2.
如果制作出我们所能想到的 符合规则的最小分子, 它们能凸显我们的规则, 而且名字都很熟悉: 水、氨和甲烷, H₂O 、NH3 和 CH4。 “氢气”、“氧气” 和 “氮气”, 我们使用(和构成原子)相同的名字, 来为这三个双原子分子命名。 它们依然遵循规则, 因为它们之间分别有 一个、两个和三个键。 这就是为什么氧气被称为 “O2”。
I can show you combustion. Here's carbon dioxide, CO2. Above it, let's place water and oxygen, and beside it, some flammable fuels. These fuels are made of just hydrogen and carbon. That's why we call them hydrocarbons. We're very creative.
我可以给大家展示何谓燃烧。 这是二氧化碳,CO2。 我们在上面放上水和氧气, 然后在旁边放一些可燃燃料。 这些燃料只由氢和碳组成。 [ 丙烷、丁烷、辛烷 ] 因此被称为碳氢化合物。 我们的命名真有创意。
(Laughter)
(笑声)
So when these crash into molecules of oxygen, as they do in your engine or in your barbecues, they release energy and they reassemble, and every carbon atom ends up at the center of a CO2 molecule, holding on to two oxygens, and all the hydrogens end up as parts of waters, and everybody follows the rules. They are not optional, and they're not optional for bigger molecules either, like these three. This is our favorite vitamin sitting next to our favorite drug,
当这些分子和氧气碰撞, 就像在引擎或者烧烤中一样, 它们会释放能量并重新组合, 每一个碳原子最终会变成 一个二氧化碳分子的中心, 抓住两个氧原子, 而所有的氢原子最终会 变成水分子的一部分, 并且每个原子都遵循了规则。 这些规则不是可有可无的, 更大的分子也必须遵循规则, 比如说这三个。 这是我们最喜欢的维生素, [ 维生素 C ] 旁边是大家最爱嗑的药, [ 咖啡因 ]
(Laughter)
(笑声)
and morphine is one of the most important stories in medical history. It marks medicine's first real triumph over physical pain, and every molecule has a story, and they are all published. They're written by scientists, and they're read by other scientists, so we have handy representations to do this quickly on paper, and I need to teach you how to do that.
以及吗啡——医学史中 最重要的故事之一。 它标志着医学第一次 真正战胜了肉体的疼痛。 每一个分子都有一个故事, 并且都已经出版了。 这些故事由科学家书写, 供其他科学家阅读, 所以我们有了一些方便的表达式, 能在纸上快捷地画出分子, 我也要教各位如何做到。
So we lay epinephrine flat on a page, and then we replace all the spheres with simple letters, and then the bonds that lie in the plane of the page, they just become regular lines, and the bonds that point forwards and backwards, they become little triangles, either solid or dashed to indicate depth. We don't actually draw these carbons. We save time by just hiding them. They're represented by corners between the bonds, and we also hide every hydrogen that's bonded to a carbon. We know they're there whenever a carbon is showing us any fewer than four bonds. The last thing that's done is the bonds between OH and NH. We just get rid of those to make it cleaner, and that's all there is to it. This is the professional way to draw molecules. This is what you see on Wikipedia pages.
让我们把肾上腺素平放在一张纸上, 然后用简单的字母 取代所有的球体, 那些位于纸张同一平面的化学键 就变成了普通的线条, 而指向纸张前面或者后面的键 则变成了小三角, 小三角的虚实则表示了深度。 我们不用实际画出这些碳原子, 而是把它们省略,以节约时间。 碳由键之间的交点来表示。 我们同样也省略每个碳上连着的氢, 因为每当一个碳上 显示的键不足四个时, 我们就知道那里有氢。 最后要处理一下 OH 和 NH 之间的键。 我们把这些键清除,让它更简洁, 这样就画完了。 这就是分子的专业画法。 你在维基页面上看到的就是这种图像。
It takes a little bit of practice, but I think everyone here could do it, but for today, this is epinephrine. This is also called adrenaline. They're one and the same. It's made by your adrenal glands. You have this molecule swimming through your body right now. It's a natural molecule. This EpiPen would just give you a quick quintillion more of them.
它需要一些练习, 但我相信在座的每一位都能做到, 不过今天只需要知道, 这是肾上腺素(epinephrine), 也可以称为 adrenaline, 两者是同一个东西。 它是由肾上腺分泌的。 这个分子现在正在你的体内游动。 它是一种天然分子。 这支笔不过是快速给你提供了 一百万的三次方个这种分子。
(Laughter)
(笑声)
We can extract epinephrine from the adrenal glands of sheep or cattle, but that's not where this stuff comes from. We make this epinephrine in a factory by stitching together smaller molecules that come mostly from petroleum. And this is 100 percent synthetic. And that word, "synthetic," makes some of us uncomfortable. It's not like the word "natural," which makes us feel safe. But these two molecules, they cannot be distinguished. We're not talking about two cars that are coming off an assembly line here. A car can have a scratch on it, and you can't scratch an atom. These two are identical in a surreal, almost mathematical sense. At this atomic scale, math practically touches reality. And a molecule of epinephrine ... it has no memory of its origin. It just is what it is, and once you have it, the words "natural" and "synthetic," they don't matter, and nature synthesizes this molecule just like we do, except nature is much better at this than we are.
我们可以从羊或者牛的肾上腺 提取肾上腺素, 但那并不是这支东西的来源。 这支肾上腺素是在工厂里生产的—— 把大部分从石油中提取的 更小的分子缝合在一起。 这是百分之百合成的。 “合成” 这个词会让一些人 感觉不舒服。 它不像 “天然” 这个词一样 让我们感到安全。 但这两个分子是无法区分的。 我们讨论的不是从流水线上 下来的两辆汽车。 一辆车可以有刮痕, 但你不能刮花一个原子。 这两个分子在一种超现实的、 近乎数学的意义上是完全相同的。 在原子大小的领域里, 数学可以说是触及了现实。 而且一个肾上腺素的分子…… 它对自己的来源没有记忆。 它就是它自己, 一旦生成, “天然” 或者 “合成” 这些字眼 就都不重要了, 而且自然合成这个分子的方法 和我们一样, 只不过自然要比我们做得更好。
Before there was life on earth, all the molecules were small, simple: carbon dioxide, water, nitrogen, just simple things. The emergence of life changed that. Life brought biosynthetic factories that are powered by sunlight, and inside these factories, small molecules crash into each other and become large ones: carbohydrates, proteins, nucleic acids, multitudes of spectacular creations. Nature is the original organic chemist, and her construction also fills our sky with the oxygen gas we breathe, this high-energy oxygen.
在地球上出现生命以前, 所有的分子都很小、很简单: 二氧化碳、水、氮气, 只是一些简单的东西。 生命的出现改变了这一点。 生命带来了由阳光驱动的 生物合成工厂, 在这些工厂里面, 小分子互相碰撞, 变成大分子:碳水化合物、 蛋白质、核酸, 无数令人叹为观止的创造物。 自然是最初的有机化学家, 她的创造也让天空 充满了我们呼吸的氧气, 这种高能量的氧。
All of these molecules are infused with the energy of the sun. They store it like batteries. So nature is made of chemicals. Maybe you guys can help me to reclaim this word, "chemical," because it has been stolen from us. It doesn't mean toxic, and it doesn't mean harmful, and it doesn't mean man-made or unnatural. It just means "stuff," OK?
所有这些分子都被 注入了太阳的能量, 像电池一样储存着。 所以,自然是由化学品构成的。 也许你们能帮我夺回 “化学品” 这个词, 因为它已经被妖魔化了。 它不代表有毒或是有害, 也不代表人工制造或者非天然。 它只是意味着 “东西”,好吧?
(Laughter)
(笑声)
You can't have chemical-free lump charcoal. That is ridiculous.
不含化学品的木炭是不存在的。 那太荒谬了。
(Laughter)
(笑声)
And I'd like to do one more word. The word "natural" doesn't mean "safe," and you all know that. Plenty of nature's chemicals are quite toxic, and others are delicious, and some are both ...
我想再谈谈另一个词。 “天然” 并不意味着 “安全”, 你们都知道这点。 大自然中有不少有毒的化学物质, 另一些则很美味, 还有一些则两者兼具……
(Laughter)
(笑声)
toxic and delicious.
有毒又美味。
The only way to tell whether something is harmful is to test it, and I don't mean you guys. Professional toxicologists: we have these people. They're well-trained, and you should trust them like I do.
唯一辨别某样东西 是否有害的办法, 就是对它进行检测, 我不是说让大家自己做实验。 专业的毒理专家:我们有这些人。 他们接受过很好的训练, 你应该像我一样相信他们。
So nature's molecules are everywhere, including the ones that have decomposed into these black mixtures that we call petroleum. We refine these molecules. There's nothing unnatural about them. We purify them. Now, our dependence on them for energy -- that means that every one of those carbons gets converted into a molecule of CO2. That's a greenhouse gas that is messing up our climate. Maybe knowing this chemistry will make that reality easier to accept for some people, I don't know, but these molecules are not just fossil fuels. They're also the cheapest available raw materials for doing something that we call synthesis. We're using them like pieces of LEGO. We have learned how to connect them or break them apart with great control. I have done a lot of this myself, and I still think it's amazing it's even possible. What we do is kind of like assembling LEGO by dumping boxes of it into washing machines, but it works.
自然的分子无处不在, 包括那些已经降解成 我们称之为石油的黑色混合物。 我们精炼这些分子。 它们没有任何不天然的地方。 我们将它们提纯。 我们依靠它们获取能源—— 这意味着每一个碳原子 会被转换成一个二氧化碳分子。 这是一种温室气体, 会把我们的气候弄得一塌糊涂。 也许知道这个化学知识 能让一些人更容易接受这一现实吧, 但这些分子并不只是化石燃料。 它们也是现有最便宜的原材料, 能用来进行 “合成” 这一过程。 我们像拼乐高积木一样 使用这些分子。 我们学会了如何连接它们, 或以精准的控制将它们拆开。 我自己就做过很多合成, 我依然觉得能做到这种事 实在是不可思议。 我们所做的就像是 把很多盒积木倒进洗衣机里 以此来组装乐高, 但是竟然能成功。
We can make molecules that are exact copies of nature, like epinephrine, or we can make creations of our own from scratch, like these two. One of these eases the symptoms of multiple sclerosis; the other one cures a type of blood cancer that we call T-cell lymphoma. A molecule with the right size and shape, it's like a key in a lock, and when it fits, it interferes with the chemistry of a disease. That's how drugs work. Natural or synthetic, they're all just molecules that happen to fit snugly somewhere important.
我们可以制造和自然界 完全相同的分子,比如肾上腺素, 或者可以从头开始创造 自己的分子,就像这两个。 其中一个能缓解 多发性硬化症的症状; 另一个能治疗一种 叫做 T 细胞淋巴瘤的血癌。 一个大小和形状合适的分子 就像往锁里插入钥匙, 当它匹配的时候, 就能干扰疾病的化学机制。 药物的原理就是这样。 不管是天然的还是合成的, 它们全都不过是分子, 碰巧能完美契合某个重要的位置。
But nature is much better at making them than we are, so hers look more impressive than ours, like this one. This is called vancomycin. She gave this majestic beast two chlorine atoms to wear like a pair of earrings. We found vancomycin in a puddle of mud in a jungle in Borneo in 1953. It's made by a bacteria. We can't synthesize this cost-efficiently in a lab. It's too complicated for us, but we can harvest it from its natural source, and we do, because this is one of our most powerful antibiotics. And new molecules are reported in our literature every day. We make them or we find them in every corner of this planet. And that's where drugs come from, and that's why your doctors have amazing powers ...
不过自然在制造分子方面 比我们强得多, 所以自然的分子比我们的 更令人称奇, 就像这个。 这个分子叫做万古霉素。 她给这只壮观的大个头 添了两个氯原子, 就像戴了一对耳环。 我们是 1953 年在婆罗洲丛林的 泥潭里发现万古霉素的。 它是由一种细菌生成的。 我们无法在实验室里 低成本地合成它。 它对我们来说太复杂了, 不过我们可以从其天然来源中采集, 我们也在这么做, 因为它是最强效的抗生素之一。 我们的文献每天都在报告新的分子。 我们制造分子,或是在这个星球的 每一个角落发现它们。 这就是药物的来源, 这也是为什么你们的医生 拥有惊人的神力……
(Laughter)
(笑声)
to cure deadly infections and everything else.
去治疗致命的感染和其他各种问题。
Being a physician today is like being a knight in shining armor. They fight battles with courage and composure, but also with good equipment. So let's not forget the role of the blacksmith in this picture, because without the blacksmith, things would look a little different ...
今天的医生就像是 身穿闪亮盔甲的骑士。 他们踏上战场时, 不仅心怀勇气与镇静, 还身着出色的装备。 所以,我们不要忘记 这张图中铁匠的功劳, 因为没有铁匠打造的盔甲, 事情就会变得有点不同了……
(Laughter)
(笑声)
But this science is bigger than medicine. It is oils and solvents and flavors, fabrics, all plastics, the cushions that you're sitting on right now -- they're all manufactured, and they're mostly carbon, so that makes all of it organic chemistry. This is a rich science.
但这门科学的范畴超越了医学。 它是油、溶剂、香精、 布料、所有的塑料、 你现在坐着的椅垫—— 都是制造出的产品, 它们大部分是碳, 也就是说这一切都是有机化学。 这是一门丰富的科学。
I left out a lot today: phosphorus and sulfur and the other atoms, and why they all bond the way they do, and symmetry and non-bonding electrons, and atoms that are charged, and reactions and their mechanisms, and it goes on and on and on, and synthesis takes a long time to learn.
我今天还有很多没讲: 磷和硫和其他原子、 它们为什么以这种方式连接、 对称性、 孤对电子、 带电的原子、 化学反应和机制, 还有很多很多, 合成也需要花很长时间学习。
But I didn't come here to teach you guys organic chemistry -- I just wanted to show it to you, and I had a lot of help with that today from a young man named Weston Durland, and you've already seen him. He's an undergraduate student in chemistry, and he also happens to be pretty good with computer graphics.
但是,我在这里 不是为了教大家有机化学—— 我只是想把有机化学展现给大家看, 今天一位叫韦斯顿·杜兰德 (Weston Durland)的年轻人 为我提供了很多帮助, 你们已经看到他了, 他是化学专业的本科生, 刚好对计算机图像也很在行。
(Laughter)
(笑声)
So Weston designed all the moving molecules that you saw today. He and I wanted to demonstrate through the use of graphics like these to help someone talk about this intricate science. But our main goal was just to show you that organic chemistry is not something to be afraid of. It is, at its core, a window through which the beauty of the natural world looks richer.
今天,大家看到的所有会动的分子 都是韦斯顿设计的。 他和我想通过这样的图像演示, 来帮助讲解这门复杂的科学。 但我们的主要目标只是向大家展示 没有必要去害怕有机化学。 它本质上是一扇窗, 透过这扇窗户, 大自然的美好将看起来更加丰富。
Thank you.
谢谢。
(Applause)
(掌声)