A crash course in organic chemistry | Jakob Magolan

265,937 views ・ 2018-07-27

TED


Please double-click on the English subtitles below to play the video.

00:12
I'd like you to ask yourself,
0
12623
1432
00:14
what do you feel when you hear the words "organic chemistry?"
1
14973
3789
00:18
What comes to mind?
2
18786
1166
00:20
There is a course offered at nearly every university,
3
20763
3643
00:24
and it's called Organic Chemistry,
4
24430
1889
00:26
and it is a grueling, heavy introduction to the subject,
5
26343
2769
00:30
a flood of content that overwhelms students,
6
30252
2974
00:33
and you have to ace it if you want to become a doctor or a dentist
7
33250
4190
00:37
or a veterinarian.
8
37464
1362
00:38
And that is why so many students perceive this science like this ...
9
38850
3936
00:44
as an obstacle in their path,
10
44127
1970
00:46
and they fear it and they hate it
11
46121
2164
00:48
and they call it a weed-out course.
12
48309
2143
00:50
What a cruel thing for a subject to do to young people,
13
50476
2825
00:53
weed them out.
14
53325
1189
00:55
And this perception spread beyond college campuses long ago.
15
55538
3780
00:59
There is a universal anxiety about these two words.
16
59342
3672
01:04
I happen to love this science,
17
64963
2426
01:07
and I think this position in which we have placed it
18
67413
2500
01:09
is inexcusable.
19
69937
1741
01:11
It's not good for science, and it's not good for society,
20
71702
3861
01:15
and I don't think it has to be this way.
21
75587
2567
01:18
And I don't mean that this class should be easier. It shouldn't.
22
78178
4682
01:23
But your perception of these two words
23
83819
3817
01:28
should not be defined by the experiences of premed students
24
88884
4389
01:33
who frankly are going through a very anxious time of their lives.
25
93297
3160
01:37
So I'm here today because I believe
26
97720
2455
01:40
that a basic knowledge of organic chemistry is valuable,
27
100199
2633
01:42
and I think that it can be made accessible to everybody,
28
102856
4612
01:47
and I'd like to prove that to you today.
29
107492
2413
01:49
Would you let me try?
30
109929
1381
01:51
Audience: Yeah!
31
111334
1528
01:52
Jakob Magolan: All right, let's go for it.
32
112886
3063
01:55
(Laughter)
33
115973
1254
01:57
Here I have one of these overpriced EpiPens.
34
117251
2793
02:00
Inside it is a drug called epinephrine.
35
120540
2281
02:03
Epinephrine can restart the beat of my heart,
36
123250
3134
02:06
or it could stop a life-threatening allergic reaction.
37
126408
2565
02:08
An injection of this right here will do it.
38
128997
3364
02:13
It would be like turning the ignition switch
39
133076
2095
02:15
in my body's fight-or-flight machinery.
40
135195
2030
02:17
My heart rate, my blood pressure would go up so blood could rush to my muscles.
41
137249
3817
02:21
My pupils would dilate. I would feel a wave of strength.
42
141090
2936
02:24
Epinephrine has been the difference between life and death for many people.
43
144050
5150
02:29
This is like a little miracle that you can hold in your fingers.
44
149224
3195
02:33
Here is the chemical structure of epinephrine.
45
153459
3302
02:37
This is what organic chemistry looks like.
46
157753
2207
02:39
It looks like lines and letters ...
47
159984
2261
02:43
No meaning to most people.
48
163362
1597
02:45
I'd like to show you what I see when I look at that picture.
49
165740
2850
02:49
I see a physical object
50
169645
1839
02:53
that has depth and rotating parts,
51
173071
2350
02:55
and it's moving.
52
175445
1229
02:58
We call this a compound or a molecule,
53
178864
2104
03:00
and it is 26 atoms that are stitched together by atomic bonds.
54
180992
5746
03:07
The unique arrangement of these atoms gives epinephrine its identity,
55
187443
4468
03:11
but nobody has ever actually seen one of these,
56
191935
2311
03:14
because they're very small,
57
194270
1454
03:15
so we're going to call this an artistic impression,
58
195748
3148
03:18
and I want to explain to you how small this is.
59
198920
2230
03:22
In here, I have less than half a milligram of it dissolved in water.
60
202618
4144
03:26
It's the mass of a grain of sand.
61
206786
1573
03:28
The number of epinephrine molecules in here is one quintillion.
62
208383
3936
03:33
That's 18 zeroes.
63
213528
1459
03:35
That number is hard to visualize.
64
215011
1572
03:37
Seven billion of us on this planet?
65
217336
2685
03:40
Maybe 400 billion stars in our galaxy?
66
220877
4755
03:45
You're not even close.
67
225656
1151
03:46
If you wanted to get into the right ballpark,
68
226831
2097
03:48
you'd have to imagine every grain of sand
69
228952
2717
03:51
on every beach, under all the oceans and lakes,
70
231693
3596
03:55
and then shrink them all so they fit in here.
71
235313
2722
03:59
Epinephrine is so small we will never see it,
72
239821
2850
04:02
not through any microscope ever,
73
242695
2356
04:05
but we know what it looks like,
74
245995
1549
04:07
because it shows itself through some sophisticated machines
75
247568
3809
04:11
with fancy names
76
251401
2132
04:13
like "nuclear magnetic resonance spectrometers."
77
253557
2405
04:17
So visible or not, we know this molecule very well.
78
257398
3271
04:20
We know it is made of four different types of atoms,
79
260693
2443
04:23
hydrogen, carbon, oxygen and nitrogen.
80
263160
1913
04:25
These are the colors we typically use for them.
81
265097
2767
04:27
Everything in our universe is made of little spheres
82
267888
2627
04:30
that we call atoms.
83
270539
1176
04:31
There's about a hundred of these basic ingredients,
84
271739
2402
04:34
and they're all made from three smaller particles:
85
274165
2359
04:36
protons, neutrons, electrons.
86
276548
1636
04:38
We arrange these atoms into this familiar table.
87
278208
2912
04:42
We give them each a name and a number.
88
282755
2223
04:45
But life as we know it doesn't need all of these,
89
285002
2326
04:47
just a smaller subset, just these.
90
287352
2515
04:50
And there are four atoms in particular that stand apart from the rest
91
290671
3303
04:53
as the main building blocks of life,
92
293998
2033
04:56
and they are the same ones that are found in epinephrine:
93
296055
3366
04:59
hydrogen, carbon, nitrogen and oxygen.
94
299445
3038
05:04
Now what I tell you next is the most important part.
95
304512
2915
05:08
When these atoms connect to form molecules,
96
308443
2856
05:11
they follow a set of rules.
97
311323
1729
05:13
Hydrogen makes one bond,
98
313076
2262
05:15
oxygen always makes two,
99
315362
1746
05:17
nitrogen makes three
100
317132
1432
05:18
and carbon makes four.
101
318588
1524
05:20
That's it.
102
320857
1421
05:22
HONC -- one, two, three, four.
103
322302
1685
05:25
If you can count to four, and you can misspell the word "honk,"
104
325962
3716
05:29
you're going to remember this for the rest of your lives.
105
329702
2668
05:32
(Laughter)
106
332394
1652
05:34
Now here I have four bowls with these ingredients.
107
334070
2423
05:36
We can use these to build molecules.
108
336517
2764
05:40
Let's start with epinephrine.
109
340828
1579
05:43
Now, these bonds between atoms, they're made of electrons.
110
343464
4181
05:48
Atoms use electrons like arms to reach out and hold their neighbors.
111
348454
3293
05:51
Two electrons in each bond, like a handshake,
112
351771
2122
05:53
and like a handshake, they are not permanent.
113
353917
2097
05:56
They can let go of one atom and grab another.
114
356038
2143
05:58
That's what we call a chemical reaction,
115
358205
1906
06:00
when atoms exchange partners and make new molecules.
116
360135
2861
06:03
The backbone of epinephrine is made mostly of carbon atoms,
117
363020
3585
06:06
and that's common.
118
366629
1158
06:07
Carbon is life's favorite structural building material,
119
367811
2683
06:10
because it makes a good number of handshakes
120
370518
3173
06:13
with just the right grip strength.
121
373715
2008
06:15
That's why we define organic chemistry as the study of carbon molecules.
122
375747
3721
06:20
Now, if we build the smallest molecules we can think of that follow our rules,
123
380559
4963
06:25
they highlight our rules, and they have familiar names:
124
385546
2572
06:28
water, ammonia and methane, H20 and NH3 and CH4.
125
388142
3785
06:33
The words "hydrogen," "oxygen" and "nitrogen" --
126
393739
2461
06:36
we use the same words
127
396224
2268
06:38
to name these three molecules that have two atoms each.
128
398516
2651
06:41
They still follow the rules,
129
401191
1341
06:42
because they have one, two and three bonds between them.
130
402556
2668
06:45
That's why oxygen gets called O2.
131
405248
1725
06:48
I can show you combustion.
132
408449
1945
06:51
Here's carbon dioxide, CO2.
133
411323
2421
06:53
Above it, let's place water and oxygen, and beside it, some flammable fuels.
134
413768
4904
06:58
These fuels are made of just hydrogen and carbon.
135
418696
2302
07:01
That's why we call them hydrocarbons. We're very creative.
136
421022
2716
07:03
(Laughter)
137
423762
1456
07:05
So when these crash into molecules of oxygen,
138
425242
2143
07:07
as they do in your engine or in your barbecues,
139
427409
3714
07:12
they release energy and they reassemble,
140
432091
1993
07:14
and every carbon atom ends up at the center of a CO2 molecule,
141
434108
2992
07:17
holding on to two oxygens,
142
437124
1242
07:18
and all the hydrogens end up as parts of waters,
143
438390
2449
07:20
and everybody follows the rules.
144
440863
1992
07:22
They are not optional,
145
442879
1318
07:24
and they're not optional for bigger molecules either,
146
444221
2478
07:26
like these three.
147
446723
1418
07:29
This is our favorite vitamin
148
449347
2175
07:31
sitting next to our favorite drug,
149
451546
1650
07:33
(Laughter)
150
453220
1246
07:34
and morphine is one of the most important stories in medical history.
151
454490
3739
07:38
It marks medicine's first real triumph over physical pain,
152
458253
2912
07:41
and every molecule has a story,
153
461189
2004
07:43
and they are all published.
154
463217
1584
07:44
They're written by scientists, and they're read by other scientists,
155
464825
3466
07:48
so we have handy representations to do this quickly on paper,
156
468315
3075
07:51
and I need to teach you how to do that.
157
471414
1859
07:53
So we lay epinephrine flat on a page,
158
473297
2775
07:56
and then we replace all the spheres with simple letters,
159
476096
2680
07:58
and then the bonds that lie in the plane of the page,
160
478800
2495
08:01
they just become regular lines,
161
481319
1809
08:03
and the bonds that point forwards and backwards,
162
483152
2253
08:05
they become little triangles,
163
485429
1398
08:06
either solid or dashed to indicate depth.
164
486851
2139
08:09
We don't actually draw these carbons.
165
489330
2231
08:11
We save time by just hiding them.
166
491585
2811
08:14
They're represented by corners between the bonds,
167
494897
3136
08:18
and we also hide every hydrogen that's bonded to a carbon.
168
498057
3633
08:22
We know they're there
169
502583
1158
08:23
whenever a carbon is showing us any fewer than four bonds.
170
503765
2898
08:27
The last thing that's done is the bonds between OH and NH.
171
507853
2936
08:31
We just get rid of those to make it cleaner,
172
511432
2088
08:33
and that's all there is to it.
173
513544
1477
08:35
This is the professional way to draw molecules.
174
515045
2580
08:37
This is what you see on Wikipedia pages.
175
517649
2411
08:42
It takes a little bit of practice, but I think everyone here could do it,
176
522793
3762
08:46
but for today, this is epinephrine.
177
526579
2726
08:49
This is also called adrenaline. They're one and the same.
178
529886
2928
08:52
It's made by your adrenal glands.
179
532838
1612
08:54
You have this molecule swimming through your body right now.
180
534474
2952
08:57
It's a natural molecule.
181
537450
1690
08:59
This EpiPen would just give you a quick quintillion more of them.
182
539164
4244
09:03
(Laughter)
183
543432
1650
09:05
We can extract epinephrine
184
545106
3191
09:08
from the adrenal glands of sheep or cattle,
185
548321
3420
09:11
but that's not where this stuff comes from.
186
551765
2334
09:14
We make this epinephrine in a factory
187
554123
2868
09:17
by stitching together smaller molecules that come mostly from petroleum.
188
557015
5239
09:23
And this is 100 percent synthetic.
189
563322
1709
09:25
And that word, "synthetic," makes some of us uncomfortable.
190
565862
3253
09:29
It's not like the word "natural," which makes us feel safe.
191
569964
3295
09:33
But these two molecules, they cannot be distinguished.
192
573283
3642
09:38
We're not talking about two cars that are coming off an assembly line here.
193
578263
3896
09:42
A car can have a scratch on it,
194
582183
2041
09:44
and you can't scratch an atom.
195
584248
1855
09:46
These two are identical in a surreal, almost mathematical sense.
196
586127
4548
09:50
At this atomic scale, math practically touches reality.
197
590699
3101
09:54
And a molecule of epinephrine ...
198
594128
1619
09:56
it has no memory of its origin.
199
596779
1699
09:58
It just is what it is,
200
598502
1405
09:59
and once you have it,
201
599931
1151
10:01
the words "natural" and "synthetic," they don't matter,
202
601106
4411
10:06
and nature synthesizes this molecule just like we do,
203
606284
3212
10:09
except nature is much better at this than we are.
204
609520
2287
10:11
Before there was life on earth,
205
611831
2378
10:14
all the molecules were small, simple:
206
614233
3007
10:17
carbon dioxide, water, nitrogen,
207
617264
1651
10:20
just simple things.
208
620018
1150
10:21
The emergence of life changed that.
209
621192
1948
10:23
Life brought biosynthetic factories that are powered by sunlight,
210
623164
3236
10:26
and inside these factories, small molecules crash into each other
211
626424
3515
10:29
and become large ones: carbohydrates, proteins, nucleic acids,
212
629963
3308
10:33
multitudes of spectacular creations.
213
633295
2453
10:37
Nature is the original organic chemist,
214
637613
2325
10:40
and her construction also fills our sky with the oxygen gas we breathe,
215
640932
3423
10:44
this high-energy oxygen.
216
644379
1468
10:47
All of these molecules are infused with the energy of the sun.
217
647597
3261
10:50
They store it like batteries.
218
650882
1468
10:52
So nature is made of chemicals.
219
652810
2842
10:56
Maybe you guys can help me to reclaim this word, "chemical,"
220
656251
2937
10:59
because it has been stolen from us.
221
659212
2499
11:01
It doesn't mean toxic, and it doesn't mean harmful,
222
661735
2699
11:04
and it doesn't mean man-made or unnatural.
223
664458
2635
11:07
It just means "stuff," OK?
224
667117
3253
11:10
(Laughter)
225
670394
1521
11:11
You can't have chemical-free lump charcoal.
226
671939
4036
11:15
That is ridiculous.
227
675999
1210
11:17
(Laughter)
228
677233
1001
11:18
And I'd like to do one more word.
229
678258
1833
11:20
The word "natural" doesn't mean "safe,"
230
680932
2675
11:23
and you all know that.
231
683631
2508
11:26
Plenty of nature's chemicals are quite toxic,
232
686163
4483
11:30
and others are delicious,
233
690670
2603
11:33
and some are both ...
234
693297
1922
11:35
(Laughter)
235
695243
1371
11:36
toxic and delicious.
236
696638
1690
11:38
The only way to tell whether something is harmful
237
698813
2778
11:41
is to test it,
238
701615
1872
11:43
and I don't mean you guys.
239
703511
2158
11:45
Professional toxicologists: we have these people.
240
705693
2809
11:48
They're well-trained,
241
708526
1514
11:50
and you should trust them like I do.
242
710064
2002
11:52
So nature's molecules are everywhere,
243
712893
1770
11:54
including the ones that have decomposed
244
714687
1873
11:56
into these black mixtures that we call petroleum.
245
716584
2310
11:58
We refine these molecules.
246
718918
2230
12:01
There's nothing unnatural about them.
247
721695
1819
12:03
We purify them.
248
723538
1150
12:06
Now, our dependence on them for energy --
249
726228
2968
12:09
that means that every one of those carbons gets converted into a molecule of CO2.
250
729220
4009
12:13
That's a greenhouse gas that is messing up our climate.
251
733253
2944
12:16
Maybe knowing this chemistry will make that reality easier to accept
252
736221
3691
12:19
for some people, I don't know,
253
739936
1470
12:21
but these molecules are not just fossil fuels.
254
741430
2283
12:24
They're also the cheapest available raw materials
255
744523
2642
12:27
for doing something that we call synthesis.
256
747189
2334
12:30
We're using them like pieces of LEGO.
257
750195
2102
12:33
We have learned how to connect them or break them apart with great control.
258
753083
4287
12:37
I have done a lot of this myself,
259
757394
1606
12:39
and I still think it's amazing it's even possible.
260
759024
2349
12:41
What we do is kind of like assembling LEGO
261
761397
3302
12:44
by dumping boxes of it into washing machines,
262
764723
3032
12:47
but it works.
263
767779
1305
12:49
We can make molecules that are exact copies of nature, like epinephrine,
264
769108
4213
12:53
or we can make creations of our own from scratch, like these two.
265
773345
3992
12:57
One of these eases the symptoms of multiple sclerosis;
266
777361
4270
13:01
the other one cures a type of blood cancer that we call T-cell lymphoma.
267
781655
3787
13:05
A molecule with the right size and shape, it's like a key in a lock,
268
785466
4232
13:09
and when it fits, it interferes with the chemistry of a disease.
269
789722
3475
13:13
That's how drugs work.
270
793221
1293
13:15
Natural or synthetic,
271
795580
1620
13:17
they're all just molecules that happen to fit snugly somewhere important.
272
797224
3460
13:20
But nature is much better at making them than we are,
273
800708
2680
13:23
so hers look more impressive than ours,
274
803412
2112
13:25
like this one.
275
805548
1578
13:27
This is called vancomycin.
276
807150
1945
13:29
She gave this majestic beast two chlorine atoms
277
809119
3063
13:32
to wear like a pair of earrings.
278
812206
2185
13:34
We found vancomycin in a puddle of mud in a jungle in Borneo in 1953.
279
814415
5167
13:39
It's made by a bacteria.
280
819606
1816
13:42
We can't synthesize this cost-efficiently in a lab.
281
822355
2746
13:45
It's too complicated for us, but we can harvest it from its natural source,
282
825798
4319
13:50
and we do, because this is one of our most powerful antibiotics.
283
830141
4183
13:54
And new molecules are reported in our literature every day.
284
834348
2955
13:57
We make them or we find them in every corner of this planet.
285
837327
3230
14:01
And that's where drugs come from,
286
841982
1691
14:03
and that's why your doctors have amazing powers ...
287
843697
2245
14:05
(Laughter)
288
845966
1022
14:07
to cure deadly infections and everything else.
289
847012
2206
14:09
Being a physician today is like being a knight in shining armor.
290
849242
3715
14:13
They fight battles with courage and composure,
291
853948
2901
14:16
but also with good equipment.
292
856873
1620
14:18
So let's not forget the role of the blacksmith in this picture,
293
858517
4018
14:22
because without the blacksmith, things would look a little different ...
294
862559
3463
14:26
(Laughter)
295
866046
2093
14:28
But this science is bigger than medicine.
296
868163
2333
14:30
It is oils and solvents and flavors, fabrics, all plastics,
297
870520
6219
14:36
the cushions that you're sitting on right now --
298
876763
2270
14:39
they're all manufactured, and they're mostly carbon,
299
879057
2460
14:41
so that makes all of it organic chemistry.
300
881541
2034
14:43
This is a rich science.
301
883599
2189
14:45
I left out a lot today:
302
885812
1854
14:47
phosphorus and sulfur and the other atoms,
303
887690
3185
14:51
and why they all bond the way they do,
304
891812
2285
14:54
and symmetry
305
894121
1255
14:55
and non-bonding electrons,
306
895400
1821
14:57
and atoms that are charged,
307
897245
1544
14:58
and reactions and their mechanisms, and it goes on and on and on,
308
898813
3096
15:01
and synthesis takes a long time to learn.
309
901933
2010
15:03
But I didn't come here to teach you guys organic chemistry --
310
903967
2881
15:06
I just wanted to show it to you,
311
906872
1842
15:08
and I had a lot of help with that today from a young man named Weston Durland,
312
908738
5039
15:13
and you've already seen him.
313
913801
1476
15:16
He's an undergraduate student in chemistry,
314
916427
2151
15:18
and he also happens to be pretty good with computer graphics.
315
918602
3278
15:21
(Laughter)
316
921904
1737
15:23
So Weston designed all the moving molecules
317
923665
4088
15:27
that you saw today.
318
927777
1412
15:29
He and I wanted to demonstrate through the use of graphics like these
319
929213
3240
15:32
to help someone talk about this intricate science.
320
932477
2458
15:35
But our main goal was just to show you
321
935316
2341
15:37
that organic chemistry is not something to be afraid of.
322
937681
2959
15:41
It is, at its core, a window
323
941418
3190
15:44
through which the beauty of the natural world looks richer.
324
944632
3709
15:48
Thank you.
325
948365
1151
15:49
(Applause)
326
949540
3267
About this website

This site will introduce you to YouTube videos that are useful for learning English. You will see English lessons taught by top-notch teachers from around the world. Double-click on the English subtitles displayed on each video page to play the video from there. The subtitles scroll in sync with the video playback. If you have any comments or requests, please contact us using this contact form.

https://forms.gle/WvT1wiN1qDtmnspy7