[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:14.82,0:00:20.14,Default,,0000,0000,0000,,What I'm going to show you\Nare the astonishing molecular machines
Dialogue: 0,0:00:20.17,0:00:23.47,Default,,0000,0000,0000,,that create the living\Nfabric of your body.
Dialogue: 0,0:00:23.49,0:00:27.27,Default,,0000,0000,0000,,Now molecules are really, really tiny.
Dialogue: 0,0:00:27.30,0:00:30.18,Default,,0000,0000,0000,,And by tiny, I mean really.
Dialogue: 0,0:00:31.24,0:00:33.25,Default,,0000,0000,0000,,They're smaller\Nthan a wavelength of light,
Dialogue: 0,0:00:33.27,0:00:35.58,Default,,0000,0000,0000,,so we have no way\Nto directly observe them.
Dialogue: 0,0:00:36.35,0:00:38.69,Default,,0000,0000,0000,,But through science,\Nwe do have a fairly good idea
Dialogue: 0,0:00:38.72,0:00:40.93,Default,,0000,0000,0000,,of what's going on\Ndown at the molecular scale.
Dialogue: 0,0:00:41.40,0:00:44.18,Default,,0000,0000,0000,,So what we can do is actually\Ntell you about the molecules,
Dialogue: 0,0:00:44.20,0:00:47.44,Default,,0000,0000,0000,,but we don't really have a direct way\Nof showing you the molecules.
Dialogue: 0,0:00:47.46,0:00:49.71,Default,,0000,0000,0000,,One way around this is to draw pictures.
Dialogue: 0,0:00:49.74,0:00:52.28,Default,,0000,0000,0000,,And this idea is actually nothing new.
Dialogue: 0,0:00:52.30,0:00:54.59,Default,,0000,0000,0000,,Scientists have always created pictures
Dialogue: 0,0:00:54.61,0:00:57.40,Default,,0000,0000,0000,,as part of their thinking\Nand discovery process.
Dialogue: 0,0:00:57.42,0:01:00.30,Default,,0000,0000,0000,,They draw pictures\Nof what they're observing with their eyes,
Dialogue: 0,0:01:00.32,0:01:02.71,Default,,0000,0000,0000,,through technology\Nlike telescopes and microscopes,
Dialogue: 0,0:01:02.74,0:01:05.18,Default,,0000,0000,0000,,and also what they're thinking\Nabout in their minds.
Dialogue: 0,0:01:05.90,0:01:07.70,Default,,0000,0000,0000,,I picked two well-known examples,
Dialogue: 0,0:01:09.85,0:01:13.46,Default,,0000,0000,0000,,because they're very well-known\Nfor expressing science through art.
Dialogue: 0,0:01:13.68,0:01:17.38,Default,,0000,0000,0000,,And I start with Galileo,\Nwho used the world's first telescope
Dialogue: 0,0:01:17.41,0:01:18.59,Default,,0000,0000,0000,,to look at the Moon.
Dialogue: 0,0:01:18.62,0:01:22.02,Default,,0000,0000,0000,,And he transformed\Nour understanding of the Moon.
Dialogue: 0,0:01:22.85,0:01:24.48,Default,,0000,0000,0000,,The perception in the 17th century
Dialogue: 0,0:01:24.50,0:01:26.56,Default,,0000,0000,0000,,was the Moon was a perfect\Nheavenly sphere.
Dialogue: 0,0:01:26.88,0:01:29.86,Default,,0000,0000,0000,,But what Galileo saw\Nwas a rocky, barren world,
Dialogue: 0,0:01:29.88,0:01:32.28,Default,,0000,0000,0000,,which he expressed\Nthrough his watercolor painting.
Dialogue: 0,0:01:36.81,0:01:39.11,Default,,0000,0000,0000,,Another scientist with very big ideas,
Dialogue: 0,0:01:39.23,0:01:41.76,Default,,0000,0000,0000,,the superstar of biology\Nis Charles Darwin.
Dialogue: 0,0:01:41.78,0:01:44.32,Default,,0000,0000,0000,,And with this famous entry\Nin his notebook,
Dialogue: 0,0:01:44.35,0:01:47.19,Default,,0000,0000,0000,,he begins in the top left-hand\Ncorner with, "I think,"
Dialogue: 0,0:01:47.21,0:01:49.92,Default,,0000,0000,0000,,and then sketches out\Nthe first tree of life,
Dialogue: 0,0:01:49.94,0:01:53.17,Default,,0000,0000,0000,,which is his perception\Nof how all the species,
Dialogue: 0,0:01:53.20,0:01:56.78,Default,,0000,0000,0000,,all living things on Earth are connected\Nthrough evolutionary history --
Dialogue: 0,0:01:56.88,0:01:59.13,Default,,0000,0000,0000,,the origin of species\Nthrough natural selection
Dialogue: 0,0:01:59.15,0:02:01.48,Default,,0000,0000,0000,,and divergence\Nfrom an ancestral population.
Dialogue: 0,0:02:05.02,0:02:06.48,Default,,0000,0000,0000,,Even as a scientist,
Dialogue: 0,0:02:06.89,0:02:09.40,Default,,0000,0000,0000,,I used to go to lectures\Nby molecular biologists
Dialogue: 0,0:02:09.42,0:02:12.15,Default,,0000,0000,0000,,and find them completely incomprehensible,
Dialogue: 0,0:02:12.17,0:02:14.44,Default,,0000,0000,0000,,with all the fancy technical\Nlanguage and jargon
Dialogue: 0,0:02:14.47,0:02:16.59,Default,,0000,0000,0000,,that they would use\Nin describing their work,
Dialogue: 0,0:02:16.61,0:02:19.66,Default,,0000,0000,0000,,until I encountered\Nthe artworks of David Goodsell,
Dialogue: 0,0:02:20.19,0:02:22.93,Default,,0000,0000,0000,,who is a molecular biologist\Nat the Scripps Institute.
Dialogue: 0,0:02:22.95,0:02:26.52,Default,,0000,0000,0000,,And his pictures -- everything's accurate\Nand it's all to scale.
Dialogue: 0,0:02:27.75,0:02:30.18,Default,,0000,0000,0000,,And his work illuminated for me
Dialogue: 0,0:02:30.20,0:02:32.52,Default,,0000,0000,0000,,what the molecular world\Ninside us is like.
Dialogue: 0,0:02:33.52,0:02:36.52,Default,,0000,0000,0000,,In the top left-hand corner,\Nyou've got this yellow-green area.
Dialogue: 0,0:02:36.55,0:02:38.30,Default,,0000,0000,0000,,This is a transection through blood.
Dialogue: 0,0:02:38.32,0:02:41.48,Default,,0000,0000,0000,,The yellow-green area is the fluid\Nof blood, which is mostly water,
Dialogue: 0,0:02:41.51,0:02:44.49,Default,,0000,0000,0000,,but it's also antibodies, sugars,\Nhormones, that kind of thing.
Dialogue: 0,0:02:44.62,0:02:47.10,Default,,0000,0000,0000,,And the red region is a slice\Ninto a red blood cell.
Dialogue: 0,0:02:47.13,0:02:48.99,Default,,0000,0000,0000,,And those red molecules are hemoglobin.
Dialogue: 0,0:02:49.22,0:02:51.91,Default,,0000,0000,0000,,They are actually red;\Nthat's what gives blood its color.
Dialogue: 0,0:02:51.94,0:02:53.90,Default,,0000,0000,0000,,And hemoglobin acts as a molecular sponge
Dialogue: 0,0:02:53.93,0:02:55.60,Default,,0000,0000,0000,,to soak up the oxygen in your lungs
Dialogue: 0,0:02:55.63,0:02:57.74,Default,,0000,0000,0000,,and then carry it\Nto other parts of the body.
Dialogue: 0,0:02:57.77,0:03:00.80,Default,,0000,0000,0000,,I was very much inspired\Nby this image many years ago,
Dialogue: 0,0:03:00.82,0:03:03.37,Default,,0000,0000,0000,,and I wondered whether\Nwe could use computer graphics
Dialogue: 0,0:03:03.40,0:03:05.00,Default,,0000,0000,0000,,to represent the molecular world.
Dialogue: 0,0:03:05.02,0:03:06.18,Default,,0000,0000,0000,,What would it look like?
Dialogue: 0,0:03:07.10,0:03:08.98,Default,,0000,0000,0000,,And that's how I really began.
Dialogue: 0,0:03:10.16,0:03:12.55,Default,,0000,0000,0000,,So let's begin.
Dialogue: 0,0:03:13.70,0:03:16.48,Default,,0000,0000,0000,,This is DNA in its classic\Ndouble helix form.
Dialogue: 0,0:03:16.51,0:03:19.86,Default,,0000,0000,0000,,And it's from X-ray crystallography,\Nso it's an accurate model of DNA.
Dialogue: 0,0:03:20.29,0:03:23.26,Default,,0000,0000,0000,,If we unwind the double helix\Nand unzip the two strands,
Dialogue: 0,0:03:23.28,0:03:25.30,Default,,0000,0000,0000,,you see these things that look like teeth.
Dialogue: 0,0:03:25.33,0:03:27.14,Default,,0000,0000,0000,,Those are the letters of genetic code,
Dialogue: 0,0:03:27.17,0:03:29.44,Default,,0000,0000,0000,,the 25,000 genes\Nyou've got written in your DNA.
Dialogue: 0,0:03:29.46,0:03:32.40,Default,,0000,0000,0000,,This is what they typically talk about --\Nthe genetic code --
Dialogue: 0,0:03:32.42,0:03:34.11,Default,,0000,0000,0000,,this is what they're talking about.
Dialogue: 0,0:03:34.14,0:03:36.91,Default,,0000,0000,0000,,But I want to talk about\Na different aspect of DNA science,
Dialogue: 0,0:03:36.93,0:03:38.82,Default,,0000,0000,0000,,and that is the physical nature of DNA.
Dialogue: 0,0:03:38.84,0:03:41.43,Default,,0000,0000,0000,,It's these two strands\Nthat run in opposite directions
Dialogue: 0,0:03:41.45,0:03:43.62,Default,,0000,0000,0000,,for reasons I can't go into right now.
Dialogue: 0,0:03:43.65,0:03:45.85,Default,,0000,0000,0000,,But they physically run\Nin opposite directions,
Dialogue: 0,0:03:45.88,0:03:49.51,Default,,0000,0000,0000,,which creates a number of complications\Nfor your living cells,
Dialogue: 0,0:03:49.53,0:03:50.76,Default,,0000,0000,0000,,as you're about to see,
Dialogue: 0,0:03:50.79,0:03:53.15,Default,,0000,0000,0000,,most particularly\Nwhen DNA is being copied.
Dialogue: 0,0:03:53.17,0:03:55.09,Default,,0000,0000,0000,,And so what I'm about to show you
Dialogue: 0,0:03:55.11,0:03:59.13,Default,,0000,0000,0000,,is an accurate representation\Nof the actual DNA replication machine
Dialogue: 0,0:03:59.15,0:04:01.21,Default,,0000,0000,0000,,that's occurring right now\Ninside your body,
Dialogue: 0,0:04:01.24,0:04:03.05,Default,,0000,0000,0000,,at least 2002 biology.
Dialogue: 0,0:04:03.36,0:04:06.37,Default,,0000,0000,0000,,So DNA's entering the production line\Nfrom the left-hand side,
Dialogue: 0,0:04:06.73,0:04:09.90,Default,,0000,0000,0000,,and it hits this collection,\Nthese miniature biochemical machines,
Dialogue: 0,0:04:09.92,0:04:13.07,Default,,0000,0000,0000,,that are pulling apart the DNA strand\Nand making an exact copy.
Dialogue: 0,0:04:13.09,0:04:18.38,Default,,0000,0000,0000,,So DNA comes in and hits this blue,\Ndoughnut-shaped structure
Dialogue: 0,0:04:19.33,0:04:21.63,Default,,0000,0000,0000,,and it's ripped apart\Ninto its two strands.
Dialogue: 0,0:04:22.12,0:04:23.74,Default,,0000,0000,0000,,One strand can be copied directly,
Dialogue: 0,0:04:23.77,0:04:26.69,Default,,0000,0000,0000,,and you can see these things\Nspooling off to the bottom there.
Dialogue: 0,0:04:26.71,0:04:28.97,Default,,0000,0000,0000,,But things aren't so simple\Nfor the other strand
Dialogue: 0,0:04:28.100,0:04:30.76,Default,,0000,0000,0000,,because it must be copied backwards.
Dialogue: 0,0:04:30.79,0:04:32.90,Default,,0000,0000,0000,,So it's thrown out\Nrepeatedly in these loops
Dialogue: 0,0:04:32.92,0:04:36.96,Default,,0000,0000,0000,,and copied one section at a time,\Ncreating two new DNA molecules.
Dialogue: 0,0:04:36.99,0:04:42.27,Default,,0000,0000,0000,,Now you have billions of this machine\Nright now working away inside you,
Dialogue: 0,0:04:42.30,0:04:44.51,Default,,0000,0000,0000,,copying your DNA with exquisite fidelity.
Dialogue: 0,0:04:45.38,0:04:46.91,Default,,0000,0000,0000,,It's an accurate representation,
Dialogue: 0,0:04:46.93,0:04:50.46,Default,,0000,0000,0000,,and it's pretty much at the correct speed\Nfor what is occurring inside you.
Dialogue: 0,0:04:50.79,0:04:53.60,Default,,0000,0000,0000,,I've left out error correction\Nand a bunch of other things.
Dialogue: 0,0:04:53.63,0:04:55.39,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:04:55.91,0:04:58.03,Default,,0000,0000,0000,,This was work from a number of years ago--
Dialogue: 0,0:04:58.06,0:04:59.22,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:04:59.25,0:05:00.62,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:05:00.64,0:05:02.57,Default,,0000,0000,0000,,This is work from a number of years ago,
Dialogue: 0,0:05:02.60,0:05:04.86,Default,,0000,0000,0000,,but what I'll show you next\Nis updated science,
Dialogue: 0,0:05:04.89,0:05:06.05,Default,,0000,0000,0000,,it's updated technology.
Dialogue: 0,0:05:06.08,0:05:07.44,Default,,0000,0000,0000,,So again, we begin with DNA.
Dialogue: 0,0:05:07.46,0:05:09.18,Default,,0000,0000,0000,,And it's jiggling and wiggling there
Dialogue: 0,0:05:09.20,0:05:11.38,Default,,0000,0000,0000,,because of the surrounding\Nsoup of molecules,
Dialogue: 0,0:05:11.41,0:05:13.79,Default,,0000,0000,0000,,which I've stripped away\Nso you can see something.
Dialogue: 0,0:05:13.81,0:05:16.79,Default,,0000,0000,0000,,DNA is about two nanometers across,\Nwhich is really quite tiny.
Dialogue: 0,0:05:18.41,0:05:19.85,Default,,0000,0000,0000,,But in each one of your cells,
Dialogue: 0,0:05:20.07,0:05:23.68,Default,,0000,0000,0000,,each strand of DNA is about\N30 to 40 million nanometers long.
Dialogue: 0,0:05:24.31,0:05:26.25,Default,,0000,0000,0000,,So to keep the DNA organized
Dialogue: 0,0:05:27.98,0:05:29.98,Default,,0000,0000,0000,,and regulate access to the genetic code,
Dialogue: 0,0:05:30.00,0:05:32.14,Default,,0000,0000,0000,,it's wrapped around these\Npurple proteins --
Dialogue: 0,0:05:32.16,0:05:33.74,Default,,0000,0000,0000,,or I've labeled them purple here.
Dialogue: 0,0:05:34.27,0:05:35.85,Default,,0000,0000,0000,,It's packaged up and bundled up.
Dialogue: 0,0:05:36.28,0:05:38.68,Default,,0000,0000,0000,,All this field of view\Nis a single strand of DNA.
Dialogue: 0,0:05:39.31,0:05:42.39,Default,,0000,0000,0000,,This huge package of DNA\Nis called a chromosome.
Dialogue: 0,0:05:42.42,0:05:44.78,Default,,0000,0000,0000,,And we'll come back\Nto chromosomes in a minute.
Dialogue: 0,0:05:45.22,0:05:47.28,Default,,0000,0000,0000,,We're pulling out, we're zooming out,
Dialogue: 0,0:05:47.30,0:05:49.27,Default,,0000,0000,0000,,out through a nuclear pore,
Dialogue: 0,0:05:49.30,0:05:52.96,Default,,0000,0000,0000,,which is the gateway to this compartment\Nthat holds all the DNA,
Dialogue: 0,0:05:52.98,0:05:54.40,Default,,0000,0000,0000,,called the nucleus.
Dialogue: 0,0:05:54.56,0:05:58.79,Default,,0000,0000,0000,,All of this field of view\Nis about a semester's worth of biology,
Dialogue: 0,0:05:58.81,0:06:00.18,Default,,0000,0000,0000,,and I've got seven minutes,
Dialogue: 0,0:06:00.20,0:06:02.89,Default,,0000,0000,0000,,So we're not going to be\Nable to do that today?
Dialogue: 0,0:06:02.91,0:06:04.88,Default,,0000,0000,0000,,No, I'm being told, "No."
Dialogue: 0,0:06:05.32,0:06:08.68,Default,,0000,0000,0000,,This is the way a living cell\Nlooks down a light microscope.
Dialogue: 0,0:06:08.70,0:06:12.20,Default,,0000,0000,0000,,And it's been filmed under time-lapse,\Nwhich is why you can see it moving.
Dialogue: 0,0:06:12.23,0:06:13.81,Default,,0000,0000,0000,,The nuclear envelope breaks down.
Dialogue: 0,0:06:13.83,0:06:16.08,Default,,0000,0000,0000,,These sausage-shaped things\Nare the chromosomes,
Dialogue: 0,0:06:16.10,0:06:17.28,Default,,0000,0000,0000,,and we'll focus on them.
Dialogue: 0,0:06:17.31,0:06:21.34,Default,,0000,0000,0000,,They go through this very striking motion\Nthat is focused on these little red spots.
Dialogue: 0,0:06:23.07,0:06:27.30,Default,,0000,0000,0000,,When the cell feels it's ready to go,\Nit rips apart the chromosome.
Dialogue: 0,0:06:27.33,0:06:29.37,Default,,0000,0000,0000,,One set of DNA goes to one side,
Dialogue: 0,0:06:29.39,0:06:31.42,Default,,0000,0000,0000,,the other side gets\Nthe other set of DNA --
Dialogue: 0,0:06:31.44,0:06:33.28,Default,,0000,0000,0000,,identical copies of DNA.
Dialogue: 0,0:06:33.30,0:06:35.26,Default,,0000,0000,0000,,And then the cell splits down the middle.
Dialogue: 0,0:06:35.28,0:06:38.14,Default,,0000,0000,0000,,And again, you have billions of cells\Nundergoing this process
Dialogue: 0,0:06:38.17,0:06:39.52,Default,,0000,0000,0000,,right now inside of you.
Dialogue: 0,0:06:40.34,0:06:43.20,Default,,0000,0000,0000,,Now we're going to rewind\Nand just focus on the chromosomes,
Dialogue: 0,0:06:43.22,0:06:45.46,Default,,0000,0000,0000,,and look at its structure and describe it.
Dialogue: 0,0:06:46.39,0:06:48.81,Default,,0000,0000,0000,,So again, here we are\Nat that equator moment.
Dialogue: 0,0:06:49.79,0:06:50.99,Default,,0000,0000,0000,,The chromosomes line up.
Dialogue: 0,0:06:51.02,0:06:52.84,Default,,0000,0000,0000,,And if we isolate just one chromosome,
Dialogue: 0,0:06:52.87,0:06:55.69,Default,,0000,0000,0000,,we're going to pull it out\Nand have a look at its structure.
Dialogue: 0,0:06:55.71,0:06:59.17,Default,,0000,0000,0000,,So this is one of the biggest\Nmolecular structures that you have,
Dialogue: 0,0:06:59.20,0:07:02.25,Default,,0000,0000,0000,,at least as far as we've discovered\Nso far inside of us.
Dialogue: 0,0:07:03.23,0:07:05.20,Default,,0000,0000,0000,,So this is a single chromosome.
Dialogue: 0,0:07:05.23,0:07:07.83,Default,,0000,0000,0000,,And you have two strands of DNA\Nin each chromosome.
Dialogue: 0,0:07:07.85,0:07:09.57,Default,,0000,0000,0000,,One is bundled up into one sausage.
Dialogue: 0,0:07:09.60,0:07:12.33,Default,,0000,0000,0000,,The other strand is bundled up\Ninto the other sausage.
Dialogue: 0,0:07:12.35,0:07:15.92,Default,,0000,0000,0000,,These things that look like whiskers\Nthat are sticking out from either side
Dialogue: 0,0:07:15.94,0:07:17.84,Default,,0000,0000,0000,,are the dynamic scaffolding of the cell.
Dialogue: 0,0:07:17.87,0:07:20.78,Default,,0000,0000,0000,,They're called microtubules,\Nthat name's not important.
Dialogue: 0,0:07:20.80,0:07:23.54,Default,,0000,0000,0000,,But we're going to focus on\Nthe region labeled red here --
Dialogue: 0,0:07:23.56,0:07:26.10,Default,,0000,0000,0000,,and it's the interface between\Nthe dynamic scaffolding
Dialogue: 0,0:07:26.12,0:07:27.29,Default,,0000,0000,0000,,and the chromosomes.
Dialogue: 0,0:07:27.31,0:07:30.42,Default,,0000,0000,0000,,It is obviously central\Nto the movement of the chromosomes.
Dialogue: 0,0:07:30.44,0:07:34.01,Default,,0000,0000,0000,,We have no idea, really,\Nas to how it's achieving that movement.
Dialogue: 0,0:07:34.04,0:07:36.68,Default,,0000,0000,0000,,We've been studying this thing\Nthey call the kinetochore
Dialogue: 0,0:07:36.71,0:07:38.78,Default,,0000,0000,0000,,for over a hundred years\Nwith intense study,
Dialogue: 0,0:07:38.80,0:07:41.63,Default,,0000,0000,0000,,and we're still just beginning\Nto discover what it's about.
Dialogue: 0,0:07:41.65,0:07:44.41,Default,,0000,0000,0000,,It is made up of about\N200 different types of proteins,
Dialogue: 0,0:07:44.43,0:07:46.14,Default,,0000,0000,0000,,thousands of proteins in total.
Dialogue: 0,0:07:46.93,0:07:49.75,Default,,0000,0000,0000,,It is a signal broadcasting system.
Dialogue: 0,0:07:49.77,0:07:51.94,Default,,0000,0000,0000,,It broadcasts through chemical signals,
Dialogue: 0,0:07:51.96,0:07:54.71,Default,,0000,0000,0000,,telling the rest of the cell\Nwhen it's ready,
Dialogue: 0,0:07:54.73,0:07:57.56,Default,,0000,0000,0000,,when it feels that everything\Nis aligned and ready to go
Dialogue: 0,0:07:57.58,0:07:59.56,Default,,0000,0000,0000,,for the separation of the chromosomes.
Dialogue: 0,0:07:59.59,0:08:03.50,Default,,0000,0000,0000,,It is able to couple onto the growing\Nand shrinking microtubules.
Dialogue: 0,0:08:04.94,0:08:07.34,Default,,0000,0000,0000,,It's involved with the growing\Nof the microtubules,
Dialogue: 0,0:08:07.37,0:08:09.56,Default,,0000,0000,0000,,and it's able to transiently\Ncouple onto them.
Dialogue: 0,0:08:09.90,0:08:11.72,Default,,0000,0000,0000,,It's also an attention-sensing system.
Dialogue: 0,0:08:11.74,0:08:13.72,Default,,0000,0000,0000,,It's able to feel when the cell is ready,
Dialogue: 0,0:08:13.74,0:08:15.98,Default,,0000,0000,0000,,when the chromosome\Nis correctly positioned.
Dialogue: 0,0:08:16.00,0:08:19.81,Default,,0000,0000,0000,,It's turning green here because it feels\Nthat everything is just right.
Dialogue: 0,0:08:19.84,0:08:22.10,Default,,0000,0000,0000,,And you'll see,\Nthere's this one little last bit
Dialogue: 0,0:08:22.12,0:08:23.55,Default,,0000,0000,0000,,that's still remaining red.
Dialogue: 0,0:08:23.58,0:08:26.11,Default,,0000,0000,0000,,And it's walked away\Ndown the microtubules.
Dialogue: 0,0:08:27.69,0:08:30.87,Default,,0000,0000,0000,,That is the signal broadcasting system\Nsending out the stop signal.
Dialogue: 0,0:08:30.89,0:08:33.59,Default,,0000,0000,0000,,And it's walked away --\NI mean, it's that mechanical.
Dialogue: 0,0:08:33.61,0:08:35.18,Default,,0000,0000,0000,,It's molecular clockwork.
Dialogue: 0,0:08:35.20,0:08:37.78,Default,,0000,0000,0000,,This is how you work\Nat the molecular scale.
Dialogue: 0,0:08:38.41,0:08:40.67,Default,,0000,0000,0000,,So with a little bit\Nof molecular eye candy,
Dialogue: 0,0:08:40.70,0:08:41.90,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:08:41.92,0:08:43.87,Default,,0000,0000,0000,,we've got kinesins, the orange ones.
Dialogue: 0,0:08:43.89,0:08:46.67,Default,,0000,0000,0000,,They're little molecular courier\Nmolecules walking one way.
Dialogue: 0,0:08:46.69,0:08:49.84,Default,,0000,0000,0000,,And here are the dynein,\Nthey're carrying that broadcasting system.
Dialogue: 0,0:08:49.86,0:08:51.40,Default,,0000,0000,0000,,And they've got their long legs
Dialogue: 0,0:08:51.43,0:08:53.49,Default,,0000,0000,0000,,so they can step around\Nobstacles and so on.
Dialogue: 0,0:08:53.52,0:08:56.54,Default,,0000,0000,0000,,So again, this is all derived\Naccurately from the science.
Dialogue: 0,0:08:56.57,0:08:59.12,Default,,0000,0000,0000,,The problem is we can't show it\Nto you any other way.
Dialogue: 0,0:09:02.14,0:09:06.98,Default,,0000,0000,0000,,Exploring at the frontier of science,\Nat the frontier of human understanding,
Dialogue: 0,0:09:07.00,0:09:08.24,Default,,0000,0000,0000,,is mind-blowing.
Dialogue: 0,0:09:09.61,0:09:10.79,Default,,0000,0000,0000,,Discovering this stuff
Dialogue: 0,0:09:10.82,0:09:14.34,Default,,0000,0000,0000,,is certainly a pleasurable\Nincentive to work in science.
Dialogue: 0,0:09:14.86,0:09:16.77,Default,,0000,0000,0000,,But most medical researchers --
Dialogue: 0,0:09:17.54,0:09:21.75,Default,,0000,0000,0000,,discovering the stuff is simply steps\Nalong the path to the big goals,
Dialogue: 0,0:09:21.78,0:09:26.20,Default,,0000,0000,0000,,which are to eradicate disease,\Nto eliminate the suffering
Dialogue: 0,0:09:26.22,0:09:28.30,Default,,0000,0000,0000,,and the misery that disease causes
Dialogue: 0,0:09:28.32,0:09:30.00,Default,,0000,0000,0000,,and to lift people out of poverty.
Dialogue: 0,0:09:30.02,0:09:32.28,Default,,0000,0000,0000,,And so with my remaining time,\Nmy four minutes,
Dialogue: 0,0:09:33.22,0:09:37.42,Default,,0000,0000,0000,,I'm going to introduce you\Nto one of the most devastating
Dialogue: 0,0:09:37.43,0:09:39.21,Default,,0000,0000,0000,,and economically important diseases.
Dialogue: 0,0:09:40.27,0:09:43.48,Default,,0000,0000,0000,,Which inflicts hundreds of millions\Nof people worldwide every year.
Dialogue: 0,0:09:45.57,0:09:47.45,Default,,0000,0000,0000,,So again - sound, thank you.
Dialogue: 0,0:09:48.93,0:09:51.40,Default,,0000,0000,0000,,This parasite is an ancient organism.
Dialogue: 0,0:09:52.02,0:09:54.71,Default,,0000,0000,0000,,It has been with us\Nsince before we were human.
Dialogue: 0,0:09:55.31,0:09:57.91,Default,,0000,0000,0000,,Famous victims include\NAlexander the Great,
Dialogue: 0,0:09:58.16,0:09:59.16,Default,,0000,0000,0000,,Ghengis Khan
Dialogue: 0,0:09:59.18,0:10:00.65,Default,,0000,0000,0000,,and George Washington.
Dialogue: 0,0:10:01.96,0:10:03.92,Default,,0000,0000,0000,,This is the neck of a sleeping child
Dialogue: 0,0:10:03.96,0:10:06.31,Default,,0000,0000,0000,,just after the Sun has set.
Dialogue: 0,0:10:06.90,0:10:09.01,Default,,0000,0000,0000,,And it's feeding time for mosquitoes.
Dialogue: 0,0:10:09.67,0:10:10.81,Default,,0000,0000,0000,,It's dinner time.
Dialogue: 0,0:10:11.31,0:10:13.84,Default,,0000,0000,0000,,[The lifecycle of Malaria\NHuman Host]
Dialogue: 0,0:10:14.82,0:10:16.62,Default,,0000,0000,0000,,(Sound of mosquito buzzing)
Dialogue: 0,0:10:17.37,0:10:20.77,Default,,0000,0000,0000,,This mosquito is infected\Nwith a malaria parasite.
Dialogue: 0,0:10:20.85,0:10:22.76,Default,,0000,0000,0000,,Now, mosquitoes are usually vegetarian,
Dialogue: 0,0:10:22.80,0:10:25.83,Default,,0000,0000,0000,,they drink honey dew nectar,\Nfruit juices, that kind of thing.
Dialogue: 0,0:10:26.03,0:10:28.54,Default,,0000,0000,0000,,Only a pregnant female will bite humans
Dialogue: 0,0:10:28.66,0:10:31.81,Default,,0000,0000,0000,,seeking nutrients from blood\Nto nourish her developing eggs.
Dialogue: 0,0:10:38.46,0:10:40.84,Default,,0000,0000,0000,,During the bite she injects saliva
Dialogue: 0,0:10:41.11,0:10:43.38,Default,,0000,0000,0000,,to stop the blood from clotting
Dialogue: 0,0:10:47.10,0:10:48.90,Default,,0000,0000,0000,,and to lubricate the wound.
Dialogue: 0,0:10:51.09,0:10:53.56,Default,,0000,0000,0000,,Because she is infected with malaria,
Dialogue: 0,0:10:54.35,0:10:57.56,Default,,0000,0000,0000,,her saliva also contains\Nthe malaria parasite
Dialogue: 0,0:10:57.61,0:10:59.68,Default,,0000,0000,0000,,so it rides in during the bite.
Dialogue: 0,0:11:04.23,0:11:07.38,Default,,0000,0000,0000,,The parasite then exits the wound\Nand seeks out a blood vessel
Dialogue: 0,0:11:10.53,0:11:12.11,Default,,0000,0000,0000,,and uses the circulatory system
Dialogue: 0,0:11:12.16,0:11:16.38,Default,,0000,0000,0000,,as a massive freeway\Nheading for its first target -
Dialogue: 0,0:11:17.32,0:11:20.49,Default,,0000,0000,0000,,the core of your body's\Nblood filter system - the liver.
Dialogue: 0,0:11:22.35,0:11:24.02,Default,,0000,0000,0000,,Within two minutes of the bite,
Dialogue: 0,0:11:24.06,0:11:26.41,Default,,0000,0000,0000,,the malaria parasites arrive to liver.
Dialogue: 0,0:11:27.70,0:11:31.62,Default,,0000,0000,0000,,And sensing its arrival then looks\Nfor an exit from the blood stream.
Dialogue: 0,0:11:32.15,0:11:34.49,Default,,0000,0000,0000,,And this is where malaria\Nis particularly devious
Dialogue: 0,0:11:34.51,0:11:36.64,Default,,0000,0000,0000,,because it uses\Nthe very type of immune cell
Dialogue: 0,0:11:36.65,0:11:38.70,Default,,0000,0000,0000,,that is the resident in the blood stream.
Dialogue: 0,0:11:39.51,0:11:42.18,Default,,0000,0000,0000,,The immune system is supposed\Nto remove foreign invaders
Dialogue: 0,0:11:42.20,0:11:43.66,Default,,0000,0000,0000,,like bacteria and parasites.
Dialogue: 0,0:11:44.01,0:11:45.84,Default,,0000,0000,0000,,But somehow, we're not quite sure how,
Dialogue: 0,0:11:45.86,0:11:48.34,Default,,0000,0000,0000,,malaria uses a backdoor entry\Ninto the liver tissue.
Dialogue: 0,0:11:48.40,0:11:50.14,Default,,0000,0000,0000,,So here's that immune cell.
Dialogue: 0,0:11:50.25,0:11:52.02,Default,,0000,0000,0000,,Malaria leaves the bloodstream
Dialogue: 0,0:11:52.05,0:11:53.65,Default,,0000,0000,0000,,and infects a liver cell
Dialogue: 0,0:11:53.66,0:11:56.18,Default,,0000,0000,0000,,killing one or more liver cells\Non its way.
Dialogue: 0,0:11:56.21,0:11:58.28,Default,,0000,0000,0000,,So again, this is within\Na couple of minutes
Dialogue: 0,0:11:58.31,0:11:59.52,Default,,0000,0000,0000,,of the mosquito bite.
Dialogue: 0,0:12:00.28,0:12:01.89,Default,,0000,0000,0000,,Once it's infected a liver cell,
Dialogue: 0,0:12:01.91,0:12:04.18,Default,,0000,0000,0000,,it takes the next five or six days.
Dialogue: 0,0:12:04.23,0:12:07.39,Default,,0000,0000,0000,,It incubates,\Nit copies its DNA over and over again
Dialogue: 0,0:12:07.41,0:12:09.81,Default,,0000,0000,0000,,creating thousands of new parasites.
Dialogue: 0,0:12:10.08,0:12:13.41,Default,,0000,0000,0000,,So, it's this delay of about a week\Nsince you've had the mosquito bite
Dialogue: 0,0:12:13.45,0:12:16.38,Default,,0000,0000,0000,,before malaria symptoms start to appear.
Dialogue: 0,0:12:19.70,0:12:22.70,Default,,0000,0000,0000,,The malaria also transforms\Nits physical nature;
Dialogue: 0,0:12:22.87,0:12:24.87,Default,,0000,0000,0000,,it's heading for a new target.
Dialogue: 0,0:12:29.92,0:12:32.59,Default,,0000,0000,0000,,The next target is your red blood cells.
Dialogue: 0,0:12:38.18,0:12:40.76,Default,,0000,0000,0000,,Part of its transformation,\Nthe malaria coates itself
Dialogue: 0,0:12:41.60,0:12:45.78,Default,,0000,0000,0000,,with a coating of molecular hairs\Nthat act like velcro.
Dialogue: 0,0:12:48.60,0:12:51.74,Default,,0000,0000,0000,,To stick red blood cells\Nto the outer surface.
Dialogue: 0,0:12:51.81,0:12:55.34,Default,,0000,0000,0000,,And then they reorient themselves\Nand penetrate inside the red blood cell.
Dialogue: 0,0:12:55.37,0:12:57.90,Default,,0000,0000,0000,,This happens within 30 seconds\Nof leaving the liver.
Dialogue: 0,0:13:00.61,0:13:02.70,Default,,0000,0000,0000,,This is an aera of intense study -
Dialogue: 0,0:13:02.74,0:13:04.16,Default,,0000,0000,0000,,if we could stop this process
Dialogue: 0,0:13:04.66,0:13:07.19,Default,,0000,0000,0000,,we could create a vaccine for malaria.
Dialogue: 0,0:13:07.55,0:13:09.25,Default,,0000,0000,0000,,Once it's inside the red blood cell
Dialogue: 0,0:13:09.29,0:13:11.55,Default,,0000,0000,0000,,it can hide\Nfrom your body's immune system.
Dialogue: 0,0:13:15.40,0:13:17.36,Default,,0000,0000,0000,,It then, over the next few days,
Dialogue: 0,0:13:17.40,0:13:19.78,Default,,0000,0000,0000,,devours the contents of the infected cell
Dialogue: 0,0:13:19.91,0:13:21.71,Default,,0000,0000,0000,,and creates more parasites.
Dialogue: 0,0:13:28.70,0:13:31.13,Default,,0000,0000,0000,,It also changes the nature\Nof the red blood cell
Dialogue: 0,0:13:31.15,0:13:32.34,Default,,0000,0000,0000,,and makes it sticky
Dialogue: 0,0:13:32.36,0:13:34.90,Default,,0000,0000,0000,,so it sticks on the blood vessel walls.
Dialogue: 0,0:13:35.10,0:13:38.47,Default,,0000,0000,0000,,This gives the parasite enough time\Nto incubate and grow.
Dialogue: 0,0:13:39.23,0:13:40.43,Default,,0000,0000,0000,,Once it's ready,
Dialogue: 0,0:13:40.87,0:13:43.24,Default,,0000,0000,0000,,it then bursts out of the red blood cell
Dialogue: 0,0:13:43.36,0:13:46.43,Default,,0000,0000,0000,,spreading malaria\Nthroughout the bloodstream.
Dialogue: 0,0:13:48.58,0:13:50.76,Default,,0000,0000,0000,,Malaria victims suffer fever,
Dialogue: 0,0:13:50.85,0:13:54.53,Default,,0000,0000,0000,,lots of blood, convulsions,\Nbrain damage and coma.
Dialogue: 0,0:13:55.16,0:13:57.50,Default,,0000,0000,0000,,Countless millions have been killed by it.
Dialogue: 0,0:13:58.16,0:14:01.23,Default,,0000,0000,0000,,This year between\N200 and 300 million people
Dialogue: 0,0:14:01.25,0:14:03.12,Default,,0000,0000,0000,,will be struct down with malaria.
Dialogue: 0,0:14:03.90,0:14:06.05,Default,,0000,0000,0000,,Most people who die from the disease
Dialogue: 0,0:14:06.11,0:14:09.26,Default,,0000,0000,0000,,are pregnant women\Nand children under the age of five.
Dialogue: 0,0:14:09.73,0:14:10.100,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:14:11.02,0:14:16.22,Default,,0000,0000,0000,,(Applause)