A crash course in organic chemistry
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0:01 - 0:02I'd like you to ask yourself,
-
0:03 - 0:07what do you feel when you hear
the words "organic chemistry?" -
0:07 - 0:08What comes to mind?
-
0:09 - 0:12There is a course offered
at nearly every university, -
0:12 - 0:14and it's called Organic Chemistry,
-
0:14 - 0:17and it is a grueling, heavy
introduction to the subject, -
0:18 - 0:21a flood of content
that overwhelms students, -
0:21 - 0:25and you have to ace it if you want
to become a doctor or a dentist -
0:25 - 0:27or a veterinarian.
-
0:27 - 0:31And that is why so many students
perceive this science like this ... -
0:32 - 0:34as an obstacle in their path,
-
0:34 - 0:36and they fear it and they hate it
-
0:36 - 0:38and they call it a weed-out course.
-
0:38 - 0:41What a cruel thing for a subject
to do to young people, -
0:41 - 0:43weed them out.
-
0:44 - 0:47And this perception spread
beyond college campuses long ago. -
0:47 - 0:51There is a universal anxiety
about these two words. -
0:53 - 0:55I happen to love this science,
-
0:55 - 0:58and I think this position
in which we have placed it -
0:58 - 1:00is inexcusable.
-
1:00 - 1:04It's not good for science,
and it's not good for society, -
1:04 - 1:06and I don't think it has to be this way.
-
1:06 - 1:11And I don't mean that this class
should be easier. It shouldn't. -
1:12 - 1:16But your perception of these two words
-
1:17 - 1:21should not be defined
by the experiences of premed students -
1:21 - 1:24who frankly are going through
a very anxious time of their lives. -
1:26 - 1:28So I'm here today because I believe
-
1:28 - 1:31that a basic knowledge
of organic chemistry is valuable, -
1:31 - 1:35and I think that it can be made
accessible to everybody, -
1:35 - 1:38and I'd like to prove that to you today.
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1:38 - 1:39Would you let me try?
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1:39 - 1:41Audience: Yeah!
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1:41 - 1:44Jakob Magolan: All right, let's go for it.
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1:44 - 1:45(Laughter)
-
1:45 - 1:48Here I have one of these
overpriced EpiPens. -
1:49 - 1:51Inside it is a drug called epinephrine.
-
1:51 - 1:54Epinephrine can restart
the beat of my heart, -
1:54 - 1:57or it could stop a life-threatening
allergic reaction. -
1:57 - 2:00An injection of this
right here will do it. -
2:01 - 2:03It would be like turning
the ignition switch -
2:03 - 2:05in my body's fight-or-flight machinery.
-
2:05 - 2:09My heart rate, my blood pressure would
go up so blood could rush to my muscles. -
2:09 - 2:12My pupils would dilate.
I would feel a wave of strength. -
2:12 - 2:17Epinephrine has been the difference
between life and death for many people. -
2:17 - 2:20This is like a little miracle
that you can hold in your fingers. -
2:21 - 2:25Here is the chemical structure
of epinephrine. -
2:26 - 2:28This is what organic chemistry looks like.
-
2:28 - 2:30It looks like lines and letters ...
-
2:31 - 2:33No meaning to most people.
-
2:34 - 2:37I'd like to show you what I see
when I look at that picture. -
2:38 - 2:39I see a physical object
-
2:41 - 2:43that has depth and rotating parts,
-
2:43 - 2:45and it's moving.
-
2:47 - 2:49We call this a compound or a molecule,
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2:49 - 2:55and it is 26 atoms that are stitched
together by atomic bonds. -
2:55 - 3:00The unique arrangement of these atoms
gives epinephrine its identity, -
3:00 - 3:02but nobody has ever
actually seen one of these, -
3:02 - 3:04because they're very small,
-
3:04 - 3:07so we're going to call this
an artistic impression, -
3:07 - 3:09and I want to explain to you
how small this is. -
3:11 - 3:15In here, I have less than
half a milligram of it dissolved in water. -
3:15 - 3:16It's the mass of a grain of sand.
-
3:16 - 3:20The number of epinephrine
molecules in here is one quintillion. -
3:22 - 3:23That's 18 zeroes.
-
3:23 - 3:25That number is hard to visualize.
-
3:25 - 3:28Seven billion of us on this planet?
-
3:29 - 3:34Maybe 400 billion stars in our galaxy?
-
3:34 - 3:35You're not even close.
-
3:35 - 3:37If you wanted to get
into the right ballpark, -
3:37 - 3:40you'd have to imagine every grain of sand
-
3:40 - 3:43on every beach,
under all the oceans and lakes, -
3:43 - 3:46and then shrink them all
so they fit in here. -
3:48 - 3:51Epinephrine is so small
we will never see it, -
3:51 - 3:53not through any microscope ever,
-
3:54 - 3:56but we know what it looks like,
-
3:56 - 3:59because it shows itself
through some sophisticated machines -
3:59 - 4:02with fancy names
-
4:02 - 4:04like "nuclear magnetic
resonance spectrometers." -
4:05 - 4:09So visible or not, we know
this molecule very well. -
4:09 - 4:11We know it is made
of four different types of atoms, -
4:11 - 4:13hydrogen, carbon, oxygen and nitrogen.
-
4:13 - 4:16These are the colors
we typically use for them. -
4:16 - 4:19Everything in our universe
is made of little spheres -
4:19 - 4:20that we call atoms.
-
4:20 - 4:22There's about a hundred
of these basic ingredients, -
4:22 - 4:25and they're all made
from three smaller particles: -
4:25 - 4:26protons, neutrons, electrons.
-
4:26 - 4:29We arrange these atoms
into this familiar table. -
4:31 - 4:33We give them each a name and a number.
-
4:33 - 4:35But life as we know it
doesn't need all of these, -
4:35 - 4:38just a smaller subset, just these.
-
4:39 - 4:42And there are four atoms in particular
that stand apart from the rest -
4:42 - 4:44as the main building blocks of life,
-
4:44 - 4:47and they are the same ones
that are found in epinephrine: -
4:47 - 4:50hydrogen, carbon, nitrogen and oxygen.
-
4:53 - 4:55Now what I tell you next
is the most important part. -
4:56 - 4:59When these atoms
connect to form molecules, -
4:59 - 5:01they follow a set of rules.
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5:01 - 5:03Hydrogen makes one bond,
-
5:03 - 5:05oxygen always makes two,
-
5:05 - 5:07nitrogen makes three
-
5:07 - 5:08and carbon makes four.
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5:09 - 5:10That's it.
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5:10 - 5:12HONC -- one, two, three, four.
-
5:14 - 5:18If you can count to four,
and you can misspell the word "honk," -
5:18 - 5:20you're going to remember this
for the rest of your lives. -
5:20 - 5:22(Laughter)
-
5:22 - 5:24Now here I have four bowls
with these ingredients. -
5:25 - 5:27We can use these to build molecules.
-
5:29 - 5:30Let's start with epinephrine.
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5:31 - 5:36Now, these bonds between atoms,
they're made of electrons. -
5:36 - 5:40Atoms use electrons like arms
to reach out and hold their neighbors. -
5:40 - 5:42Two electrons in each bond,
like a handshake, -
5:42 - 5:44and like a handshake,
they are not permanent. -
5:44 - 5:46They can let go of one atom
and grab another. -
5:46 - 5:48That's what we call a chemical reaction,
-
5:48 - 5:51when atoms exchange partners
and make new molecules. -
5:51 - 5:55The backbone of epinephrine
is made mostly of carbon atoms, -
5:55 - 5:56and that's common.
-
5:56 - 5:58Carbon is life's favorite
structural building material, -
5:59 - 6:02because it makes
a good number of handshakes -
6:02 - 6:04with just the right grip strength.
-
6:04 - 6:07That's why we define organic chemistry
as the study of carbon molecules. -
6:09 - 6:14Now, if we build the smallest molecules
we can think of that follow our rules, -
6:14 - 6:16they highlight our rules,
and they have familiar names: -
6:16 - 6:20water, ammonia and methane,
H20 and NH3 and CH4. -
6:22 - 6:24The words "hydrogen,"
"oxygen" and "nitrogen" -- -
6:24 - 6:26we use the same words
-
6:27 - 6:29to name these three molecules
that have two atoms each. -
6:29 - 6:31They still follow the rules,
-
6:31 - 6:33because they have one, two
and three bonds between them. -
6:33 - 6:35That's why oxygen gets called O2.
-
6:36 - 6:38I can show you combustion.
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6:39 - 6:42Here's carbon dioxide, CO2.
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6:42 - 6:47Above it, let's place water and oxygen,
and beside it, some flammable fuels. -
6:47 - 6:49These fuels are made
of just hydrogen and carbon. -
6:49 - 6:52That's why we call them hydrocarbons.
We're very creative. -
6:52 - 6:53(Laughter)
-
6:53 - 6:55So when these crash
into molecules of oxygen, -
6:55 - 6:59as they do in your engine
or in your barbecues, -
7:00 - 7:02they release energy and they reassemble,
-
7:02 - 7:05and every carbon atom
ends up at the center of a CO2 molecule, -
7:05 - 7:06holding on to two oxygens,
-
7:06 - 7:09and all the hydrogens end up
as parts of waters, -
7:09 - 7:11and everybody follows the rules.
-
7:11 - 7:12They are not optional,
-
7:12 - 7:15and they're not optional
for bigger molecules either, -
7:15 - 7:16like these three.
-
7:17 - 7:20This is our favorite vitamin
-
7:20 - 7:21sitting next to our favorite drug,
-
7:21 - 7:22(Laughter)
-
7:22 - 7:26and morphine is one of the most
important stories in medical history. -
7:26 - 7:29It marks medicine's first
real triumph over physical pain, -
7:29 - 7:31and every molecule has a story,
-
7:31 - 7:33and they are all published.
-
7:33 - 7:36They're written by scientists,
and they're read by other scientists, -
7:36 - 7:39so we have handy representations
to do this quickly on paper, -
7:39 - 7:41and I need to teach you how to do that.
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7:41 - 7:44So we lay epinephrine flat on a page,
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7:44 - 7:47and then we replace all the spheres
with simple letters, -
7:47 - 7:49and then the bonds
that lie in the plane of the page, -
7:49 - 7:51they just become regular lines,
-
7:51 - 7:53and the bonds that point
forwards and backwards, -
7:53 - 7:55they become little triangles,
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7:55 - 7:57either solid or dashed to indicate depth.
-
7:57 - 8:00We don't actually draw these carbons.
-
8:00 - 8:02We save time by just hiding them.
-
8:03 - 8:06They're represented
by corners between the bonds, -
8:06 - 8:10and we also hide every hydrogen
that's bonded to a carbon. -
8:11 - 8:12We know they're there
-
8:12 - 8:15whenever a carbon is showing us
any fewer than four bonds. -
8:16 - 8:19The last thing that's done
is the bonds between OH and NH. -
8:19 - 8:22We just get rid of those
to make it cleaner, -
8:22 - 8:23and that's all there is to it.
-
8:23 - 8:26This is the professional way
to draw molecules. -
8:26 - 8:28This is what you see on Wikipedia pages.
-
8:31 - 8:35It takes a little bit of practice,
but I think everyone here could do it, -
8:35 - 8:37but for today, this is epinephrine.
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8:38 - 8:41This is also called adrenaline.
They're one and the same. -
8:41 - 8:42It's made by your adrenal glands.
-
8:42 - 8:45You have this molecule swimming
through your body right now. -
8:45 - 8:47It's a natural molecule.
-
8:47 - 8:51This EpiPen would just give you
a quick quintillion more of them. -
8:51 - 8:53(Laughter)
-
8:53 - 8:56We can extract epinephrine
-
8:56 - 9:00from the adrenal glands
of sheep or cattle, -
9:00 - 9:02but that's not
where this stuff comes from. -
9:02 - 9:05We make this epinephrine in a factory
-
9:05 - 9:10by stitching together smaller molecules
that come mostly from petroleum. -
9:11 - 9:13And this is 100 percent synthetic.
-
9:14 - 9:17And that word, "synthetic,"
makes some of us uncomfortable. -
9:18 - 9:21It's not like the word "natural,"
which makes us feel safe. -
9:21 - 9:25But these two molecules,
they cannot be distinguished. -
9:26 - 9:30We're not talking about two cars
that are coming off an assembly line here. -
9:30 - 9:32A car can have a scratch on it,
-
9:32 - 9:34and you can't scratch an atom.
-
9:34 - 9:39These two are identical in a surreal,
almost mathematical sense. -
9:39 - 9:42At this atomic scale,
math practically touches reality. -
9:42 - 9:44And a molecule of epinephrine ...
-
9:45 - 9:46it has no memory of its origin.
-
9:47 - 9:48It just is what it is,
-
9:48 - 9:49and once you have it,
-
9:49 - 9:54the words "natural" and "synthetic,"
they don't matter, -
9:54 - 9:57and nature synthesizes
this molecule just like we do, -
9:58 - 10:00except nature is much better
at this than we are. -
10:00 - 10:02Before there was life on earth,
-
10:02 - 10:05all the molecules were small, simple:
-
10:05 - 10:07carbon dioxide, water, nitrogen,
-
10:08 - 10:09just simple things.
-
10:09 - 10:11The emergence of life changed that.
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10:11 - 10:14Life brought biosynthetic factories
that are powered by sunlight, -
10:14 - 10:18and inside these factories,
small molecules crash into each other -
10:18 - 10:21and become large ones:
carbohydrates, proteins, nucleic acids, -
10:21 - 10:24multitudes of spectacular creations.
-
10:26 - 10:28Nature is the original organic chemist,
-
10:29 - 10:32and her construction also fills our sky
with the oxygen gas we breathe, -
10:32 - 10:34this high-energy oxygen.
-
10:36 - 10:39All of these molecules are infused
with the energy of the sun. -
10:39 - 10:40They store it like batteries.
-
10:41 - 10:44So nature is made of chemicals.
-
10:44 - 10:47Maybe you guys can help me
to reclaim this word, "chemical," -
10:47 - 10:50because it has been stolen from us.
-
10:50 - 10:52It doesn't mean toxic,
and it doesn't mean harmful, -
10:52 - 10:55and it doesn't mean man-made or unnatural.
-
10:55 - 10:58It just means "stuff," OK?
-
10:58 - 11:00(Laughter)
-
11:00 - 11:04You can't have
chemical-free lump charcoal. -
11:04 - 11:05That is ridiculous.
-
11:05 - 11:06(Laughter)
-
11:06 - 11:08And I'd like to do one more word.
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11:09 - 11:12The word "natural" doesn't mean "safe,"
-
11:12 - 11:14and you all know that.
-
11:14 - 11:19Plenty of nature's
chemicals are quite toxic, -
11:19 - 11:21and others are delicious,
-
11:21 - 11:23and some are both ...
-
11:23 - 11:25(Laughter)
-
11:25 - 11:26toxic and delicious.
-
11:27 - 11:30The only way to tell
whether something is harmful -
11:30 - 11:31is to test it,
-
11:32 - 11:34and I don't mean you guys.
-
11:34 - 11:37Professional toxicologists:
we have these people. -
11:37 - 11:38They're well-trained,
-
11:38 - 11:40and you should trust them like I do.
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11:41 - 11:43So nature's molecules are everywhere,
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11:43 - 11:45including the ones that have decomposed
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11:45 - 11:47into these black mixtures
that we call petroleum. -
11:47 - 11:49We refine these molecules.
-
11:50 - 11:52There's nothing unnatural about them.
-
11:52 - 11:53We purify them.
-
11:54 - 11:57Now, our dependence on them for energy --
-
11:57 - 12:01that means that every one of those carbons
gets converted into a molecule of CO2. -
12:01 - 12:04That's a greenhouse gas
that is messing up our climate. -
12:04 - 12:08Maybe knowing this chemistry
will make that reality easier to accept -
12:08 - 12:09for some people, I don't know,
-
12:09 - 12:12but these molecules
are not just fossil fuels. -
12:13 - 12:15They're also the cheapest
available raw materials -
12:15 - 12:18for doing something
that we call synthesis. -
12:18 - 12:20We're using them like pieces of LEGO.
-
12:21 - 12:25We have learned how to connect them
or break them apart with great control. -
12:25 - 12:27I have done a lot of this myself,
-
12:27 - 12:29and I still think it's amazing
it's even possible. -
12:29 - 12:33What we do is kind of like assembling LEGO
-
12:33 - 12:36by dumping boxes of it
into washing machines, -
12:36 - 12:37but it works.
-
12:37 - 12:41We can make molecules that are
exact copies of nature, like epinephrine, -
12:41 - 12:45or we can make creations of our own
from scratch, like these two. -
12:45 - 12:50One of these eases the symptoms
of multiple sclerosis; -
12:50 - 12:53the other one cures a type of blood cancer
that we call T-cell lymphoma. -
12:53 - 12:58A molecule with the right size and shape,
it's like a key in a lock, -
12:58 - 13:01and when it fits, it interferes
with the chemistry of a disease. -
13:01 - 13:03That's how drugs work.
-
13:04 - 13:05Natural or synthetic,
-
13:05 - 13:09they're all just molecules that happen
to fit snugly somewhere important. -
13:09 - 13:11But nature is much better
at making them than we are, -
13:11 - 13:14so hers look more impressive than ours,
-
13:14 - 13:15like this one.
-
13:15 - 13:17This is called vancomycin.
-
13:17 - 13:20She gave this majestic beast
two chlorine atoms -
13:20 - 13:22to wear like a pair of earrings.
-
13:22 - 13:28We found vancomycin in a puddle of mud
in a jungle in Borneo in 1953. -
13:28 - 13:29It's made by a bacteria.
-
13:30 - 13:33We can't synthesize this
cost-efficiently in a lab. -
13:34 - 13:38It's too complicated for us, but we
can harvest it from its natural source, -
13:38 - 13:42and we do, because this is
one of our most powerful antibiotics. -
13:42 - 13:45And new molecules are reported
in our literature every day. -
13:45 - 13:49We make them or we find them
in every corner of this planet. -
13:50 - 13:52And that's where drugs come from,
-
13:52 - 13:54and that's why your doctors
have amazing powers ... -
13:54 - 13:55(Laughter)
-
13:55 - 13:57to cure deadly infections
and everything else. -
13:57 - 14:01Being a physician today
is like being a knight in shining armor. -
14:02 - 14:05They fight battles
with courage and composure, -
14:05 - 14:06but also with good equipment.
-
14:07 - 14:11So let's not forget the role
of the blacksmith in this picture, -
14:11 - 14:14because without the blacksmith,
things would look a little different ... -
14:14 - 14:16(Laughter)
-
14:16 - 14:18But this science is bigger than medicine.
-
14:19 - 14:25It is oils and solvents and flavors,
fabrics, all plastics, -
14:25 - 14:27the cushions that
you're sitting on right now -- -
14:27 - 14:30they're all manufactured,
and they're mostly carbon, -
14:30 - 14:32so that makes all of it organic chemistry.
-
14:32 - 14:34This is a rich science.
-
14:34 - 14:36I left out a lot today:
-
14:36 - 14:39phosphorus and sulfur and the other atoms,
-
14:40 - 14:42and why they all bond the way they do,
-
14:42 - 14:43and symmetry
-
14:43 - 14:45and non-bonding electrons,
-
14:45 - 14:47and atoms that are charged,
-
14:47 - 14:50and reactions and their mechanisms,
and it goes on and on and on, -
14:50 - 14:52and synthesis takes a long time to learn.
-
14:52 - 14:55But I didn't come here to teach
you guys organic chemistry -- -
14:55 - 14:57I just wanted to show it to you,
-
14:57 - 15:02and I had a lot of help with that today
from a young man named Weston Durland, -
15:02 - 15:03and you've already seen him.
-
15:04 - 15:07He's an undergraduate
student in chemistry, -
15:07 - 15:10and he also happens to be
pretty good with computer graphics. -
15:10 - 15:12(Laughter)
-
15:12 - 15:16So Weston designed
all the moving molecules -
15:16 - 15:17that you saw today.
-
15:17 - 15:20He and I wanted to demonstrate
through the use of graphics like these -
15:20 - 15:23to help someone talk
about this intricate science. -
15:23 - 15:26But our main goal was just to show you
-
15:26 - 15:29that organic chemistry
is not something to be afraid of. -
15:29 - 15:33It is, at its core, a window
-
15:33 - 15:36through which the beauty
of the natural world looks richer. -
15:36 - 15:38Thank you.
-
15:38 - 15:41(Applause)
- Title:
- A crash course in organic chemistry
- Speaker:
- Jakob Magolan
- Description:
-
more » « less
Jakob Magolan is here to change your perception of organic chemistry. In an accessible talk packed with striking graphics, he teaches us the basics while breaking the stereotype that organic chemistry is something to be afraid of.
- Video Language:
- English
- Team:
closed TED
- Project:
- TEDTalks
- Duration:
- 15:53
|
Brian Greene edited English subtitles for A crash course in organic chemistry | |
|
Brian Greene edited English subtitles for A crash course in organic chemistry | |
|
Brian Greene approved English subtitles for A crash course in organic chemistry | |
|
Brian Greene edited English subtitles for A crash course in organic chemistry | |
|
Krystian Aparta accepted English subtitles for A crash course in organic chemistry | |
|
Krystian Aparta edited English subtitles for A crash course in organic chemistry | |
|
Krystian Aparta edited English subtitles for A crash course in organic chemistry | |
|
Krystian Aparta edited English subtitles for A crash course in organic chemistry |

