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00:00what's it take to make our modern world I'm David Pogue join me on a high-speed
00:20chase through the elements and beyond as we smash our way into the
00:29materials molecules and reactions it's a really cool enzyme because it makes life
00:34on earth possible that make the places we live the bodies we live in and the
00:40stuff we can't seem to live without the only thing between me and certain death
00:46is chemistry from killer snails it's when you think you've heard of everything
00:52nature will surprise you and exploding glass to the price of pepper-eating pogue
00:58pays it's got to be some easier way to learn about molecules
01:03we'll dig into the surprising way different elements combined together
01:09and blow apart
01:15in this hour we tackle one of the biggest mysteries of all the origin of life how
01:23did a bunch of chemicals get together and start acting like a cell part of the
01:27answer might be soap cell division we explore how the chemistry of life
01:33transformed the planet so everything that we eat the air that we breathe all have
01:38to do with the process of photosynthesis all right so let's find the lipids aisle I
01:43go shopping for the macro molecules of my body you're telling me that's only half the
01:50amount of fat in my body absolutely and I meet an engineer who uses nature's tools to invent new
01:58molecules humans have been using microbes to make beer and wine instead of making sake we make jet fuel
02:05beyond the elements life right now on nova
02:12the world we live in is made of atoms all listed here as elements on the periodic table
02:27they're the building blocks of everything around us and putting atoms together to make molecules and compounds is what we call chemistry
02:34and maybe the strangest event in the history of chemistry is the birth of biology how do a bunch of chemicals somehow get together to form life
02:41and if you look back at the conditions on early earth how did life get off the starting block
02:48and if you look back at the conditions on early earth how did life get off the starting block
02:56there was a turning point the evolution of a transformative series of chemical reactions that over time remade the planet even allowing us to come along
03:11but first let's see what's going on in the future of biology how do a bunch of chemicals somehow get together to form life
03:16and if you look back at the conditions on early earth how did life get off the starting block
03:20there was a turning point the evolution of a transformative series of chemical reactions
03:25first let's take a trip back to life 1.0
03:32so here's the ad
03:35planet available
03:38recently scoured by asteroids
03:41new construction
03:44now with many water views
03:48the atmosphere
03:51a fixer-upper
03:53devoid of oxygen
03:55likely full of whatever the volcanoes spewed forth
03:59gases like hydrogen sulfide and methane
04:06somehow in that very harsh environment primitive life got its start
04:12but the going stayed tough
04:14food
04:15food
04:16molecules and minerals that early organisms could use for energy
04:20consisted of whatever was left over from earth's formation
04:24or was welling up from the earth's core at places like deep sea vents
04:30water
04:32but in a surprisingly short amount of time
04:35perhaps 500 million years
04:37a new survival strategy evolved
04:40possibly the most important chemical process for life on earth today
04:45photosynthesis
04:49the ability to turn sunlight into fuel
04:56life now had access to the vast power of the sun
05:01in the words of one biologist when photosynthesis entered the picture
05:06life connected up to the cosmos
05:13so everything that we eat
05:14what we wear
05:15the air that we breathe
05:17the ecosystem services that we rely on
05:21so things like having clean water
05:23all have to do with the process of photosynthesis
05:25it's an incredibly important probably the most important process on the planet
05:33photosynthesis harnesses the power of sunlight
05:36to break down water molecules
05:39discarding the oxygen
05:41it uses the electrons from the hydrogen atoms
05:44to power the assembly of carbon dioxide molecules
05:47into carbohydrates
05:49which become both building blocks
05:52and long-term energy storage
05:54it's not an overstatement to say that
05:57all life on this planet depends on photosynthesis
06:01it's exactly where all of our food comes from
06:04directly or indirectly
06:06so understanding how this process works
06:09is so important to humanity
06:13Steve Long and Don Ort
06:16two plant biologists at the University of Illinois Urbana-Champaign
06:20along with thousands of other scientists from around the world
06:23have spent decades teasing apart the workings of photosynthesis
06:29white intensity is 900 right?
06:30right now, yeah
06:31but yeah, for baldbeer that makes sense
06:33so we're going to eat the important brain
06:35now, with that knowledge in hand
06:38there's a new international research effort
06:41based here at the University
06:43with an audacious goal
06:45the program's called RIPE
06:50realizing increased photosynthetic efficiency
06:53this year was a huge hit for the canola farmers
06:55because it was too wet
06:57so I've been wondering whether it would be worth
06:59trying to find a substitute as our test bed
07:02that'd be perfect
07:03these folks want to hack photosynthesis
07:06but why would you want to do that?
07:13because experts think the earth is about to get a whole lot more people
07:21today, the world's population is close to 8 billion
07:25and that's forecast to hit 9.7 billion by 2050
07:33raising the question
07:35will there be enough food?
07:40if you look at the current rate of which we're improving crop productivity
07:45per acre of land
07:47we're not going to get there
07:51part of the answer is going to be
07:53redesigning photosynthesis
08:00to learn more about RIPE's plans
08:02I've joined Lisa Ainsworth
08:04a USDA scientist and professor at the University of Illinois
08:09you can see just how different the height is
08:11just in walking over the morning
08:12on an early morning tour of a field
08:14that contains 600 different varieties of soybeans
08:19usually you hear about efficiency
08:22like a gas engine measured in terms of a percentage
08:25how much of the fuel is ultimately converted to energy
08:28what's the percentage efficiency for a plant?
08:31well in terms of how much of the light energy
08:34it turns into sugar
08:36it's pretty low, maybe around 3%
08:383%? that's terrible
08:40but you guys are going to help it
08:42that's the plan
08:45to improve photosynthesis
08:47two other researchers with RIPE
08:49Amanda Cavanaugh and Paul South
08:51have focused on one of its key molecules
08:56it has a very catchy name
08:58so the molecule is what we biologists call an enzyme
09:00and so it does the work
09:02enzymes are like biological workers
09:04and the enzyme is called rubisco
09:10it's RUBP or ribulose bisphosphate carboxylase oxygenase
09:18and it's for most plant biologists
09:20one of our favorite enzymes on the planet
09:22yeah, rubisco is our shortened term for it
09:24mainly because it's fun to say
09:26well it's super fun to say
09:27rubisco, of course, rubisco
09:29but it's also a really cool enzyme
09:32because it makes life on earth possible
09:36rubisco may not look so special
09:38but it is arguably the most important enzyme on the planet
09:43because of its critical role in photosynthesis
09:48rubisco's job is to grab a molecule of carbon dioxide
09:51and feed it into a molecular machine
09:54that's building carbon chains
09:57that means any carbon atom
09:59that's part of any plant anywhere
10:02got there thanks to rubisco
10:05or one of its close variants
10:08and because we eat plants
10:11or animals that ate plants
10:13that also includes just about every carbon atom in your body
10:17all approximately 800 million billion billion of them
10:25that's 26 zeros
10:30not bad, rubisco
10:32not bad
10:33yeah, so if it's ever come from a plant
10:35it had to have gone through that enzyme of rubisco
10:38that's wild
10:39how come there's not like a memorial to rubisco in Washington
10:43it seems like sort of important
10:49rubisco is important
10:51and that's why it's the most plentiful protein on earth
10:55but just because you're important
10:57doesn't mean you're entirely competent
11:02it's in this case not the best enzyme in the world
11:06it's got a hard job so it's doing its best
11:08but at the same time it exists in an atmosphere
11:10that's not predominantly carbon dioxide
11:13it's mostly oxygen
11:14and about one in every four or five reactions
11:16it grabs oxygen instead of carbon dioxide
11:19that's right
11:21rubisco screws up about a fifth of the time
11:24instead of attaching a carbon dioxide
11:27it attaches an oxygen molecule
11:29and that's trouble
11:31you're saying nature has created a screwed up
11:34little worker enzyme?
11:36yeah, so 400 million years ago
11:39when this enzyme evolved
11:40there wasn't very much oxygen in the air
11:43alright, so I'm the little rubisco enzyme
11:45and I'm like on the conveyor belt here
11:47I'm like, okay, carbon dioxide, carbon dioxide, carbon dioxide, carbon dioxide
11:50oxygen
11:51and I don't notice I accidentally grabbed an oxygen out of the box
11:55and it produces compounds that are inhibitory to photosynthesis
11:59so it kind of starts to shut things down
12:01I mean, it's been going on for billions of years
12:03and nobody's cared
12:04yeah, well
12:05I mean, it all basically works
12:06photosynthesis right now
12:08is sort of a victim of its own success
12:10rubisco certainly is
12:11so by oxygenating the atmosphere via photosynthesis
12:14you now have a huge amount of oxygen in the atmosphere
12:18but you need a carbon dioxide to make the reaction work
12:22so what happens when rubisco screws up?
12:26the result gets shipped out
12:31through a couple other parts of the cell
12:34to where the mess is taken apart and recycled
12:38all of which consumes a lot of energy
12:42if you could fix this inefficiency problem
12:45the plant might make more soybeans, corn, whatever it is?
12:48that's exactly it
12:49then they will have that energy to put towards something
12:51that we would consider useful
12:53like making more food for us to eat
12:55is this just a crazy theory
12:56or is this some indication that this could actually work?
12:58there's quite a bit of evidence that this is working
13:00so right now we have this tested in a couple of model species
13:03it is tropical in here
13:08Amanda and Paul take me to the greenhouse to see one example
13:12using two genes
13:14one from algae
13:16and the other from a pumpkin
13:18they've modified tobacco plants
13:21to address rubisco's sloppy work
13:23and why are we using tobacco plants?
13:25yeah, tobacco is a really useful model crop for us
13:28why tobacco?
13:30turns out it's one of the easiest plants to genetically manipulate
13:34which makes it a common test subject
13:37they have definitely shown improvements in plant growth
13:39and total biomass
13:40and we've been studying the rates of photosynthesis
13:42and we are pretty confident now that our model crop
13:46is successful in this pathway
13:48and now we're really interested in moving things
13:50into something we like to eat
13:53reducing the energy penalty crops pay for rubisco's mistakes
13:57could be huge
14:00in soybeans
14:02a 25% reduction
14:04could result in plants that produce
14:06more than 60 million more bushels a year
14:10this to a lot of people is an idea that might be out there
14:14but if we can get it
14:16if we can get this moonshot approach to work
14:18then we're going to have more food
14:20and so that's really what drives what I do
14:22the RIPE program is international
14:25and likely so will be the reach of any of its discoveries
14:30but work like theirs is not without controversy
14:35some of RIPE's solutions depend on crossbreeding plants
14:38chosen for their genes
14:41but other solutions like the rubisco work
14:43depend on genetic engineering
14:46also called genetic modification
14:49or GM
14:50adding new genes from other types of plants
14:53or even organisms entirely
14:56the laws governing genetically modified crops
15:00vary from country to country
15:02especially when it comes to labeling their use in food
15:06and there have been objections to some companies
15:11that patent their new crops
15:13and control who can plant them
15:15but the general scientific consensus
15:17is that they are no more dangerous than conventional crops
15:20though they need to be carefully studied
15:22for potential health and environmental effects
15:25the US unlike Europe
15:28has largely adopted GM plants
15:31an overwhelming percentage of corn, soybeans and cotton
15:36grown in the United States
15:38is genetically modified
15:40I understand there are concerns
15:45as a scientist I feel those concerns
15:48have very little validity
15:51although clearly people have become very concerned
15:55particularly in Europe
15:56because in this part of the world
15:59genetically modified crops have been grown
16:01for over 20 years
16:03this technology has spread throughout the Americas
16:06In fact, as the global population grows
16:11it's in poorer countries
16:13that RIPE's work may end up having the greatest impact
16:16especially if genetically modified foods gain acceptance
16:21the place where I see the technology needed most
16:25is actually in sub-Saharan Africa
16:28and this opposition to GM
16:30is having quite an influence in Africa
16:34it's keeping the science which is needed out
16:37and I fear that this could risk people starving
16:42when we could actually be giving them seed
16:45which would allow them to feed themselves into the future
16:49even if scientists succeed in improving photosynthesis
16:55it won't have anywhere near the dramatic impact
16:58of the original version
16:59introduced about 3 billion years ago
17:04back then, scientists believe
17:06photosynthetic cyanobacteria
17:08began cranking out oxygen as a waste product
17:14eventually, bacteria produced enough oxygen
17:17that it started to accumulate in the atmosphere
17:20which in turn, gave rise to one of life's
17:23underappreciated molecular allies
17:26the ozone layer
17:29it's in the lowest level of the stratosphere
17:32between roughly 8 and 22 miles up
17:35atmospheric research planes venture up here
17:39but not much else
17:42the ozone comes from a process even higher up in the stratosphere
17:48there, solar radiation busts up O2 molecules
17:53into individual oxygen atoms
17:55they drift down to the ozone layer
17:58where they convert O2 into O3
18:03ozone
18:04despite the name
18:07there's not that much ozone in the ozone layer
18:10less than 10 parts per million
18:13yet, it's had a profound effect on the evolution of life on Earth
18:17to find out more
18:21So ozone is O3, right?
18:24Ozone is O3
18:25I traveled to the University of California, Riverside
18:28to meet Carrie Hanson
18:31a research chemist
18:32who studies how molecules like ozone
18:35and those in sunscreens
18:37interact with light
18:38so any molecule can absorb light
18:41it turns out the ozone layer and sunscreens
18:43have a lot in common
18:45this O3 gas
18:47is out there in the atmosphere
18:50in such quantity
18:51that there's an envelope around the whole planet
18:53yeah, it's a layer
18:54think of like a sunscreen
18:56you know how we use sunscreen on our skin
18:58so it's exact same thing
18:59the ozone layer is Earth's sunscreen
19:02both the ozone layer and sunscreens
19:07protect us from the harmful effects of ultraviolet radiation
19:11or UV
19:12a kind of sunlight that
19:14unlike the colors of the rainbow
19:16we can't see
19:21on the electromagnetic spectrum
19:23visible light sits here
19:25but UV sits up here
19:29at a higher energy
19:31scientists divide it roughly
19:33into three kinds
19:35A, B, and C
19:39and while A and B aren't good for you
19:42and they're the reason to wear sunscreen
19:44it's C that's the big problem for living things
19:49because it's particularly destructive to DNA
20:01Carrie tells me how all this relates to ozone
20:05just another Sunday
20:06watching volleyball
20:07and it's kind of like
20:08volleyball
20:12oh, he's good
20:14well, if the balls were different kinds of UV
20:19in the early days of life on Earth
20:22before photosynthetic bacteria oxygenated our atmosphere
20:25there was no ozone layer
20:30and no global defense against ultraviolet radiation
20:35the most dangerous kind
20:38UVC bathed the planet
20:40which may have effectively limited where life could grow
20:45but oxygen accumulating in the atmosphere
20:48and the rise of the ozone layer
20:52changed all that
20:53the layer blocks all the UVC
20:56and most of the UVB
20:58from reaching the Earth's surface
21:01oh, good luck
21:03here's how it works
21:05when UV radiation hits a molecule of ozone
21:09it splits it into an oxygen atom
21:11and a molecule of O2
21:14the UV light has been absorbed and neutralized
21:18the lone atom quickly rejoins another molecule of O2
21:23to reform ozone
21:25the net result is a conversion of that harmful radiation
21:30into heat
21:32despite the ozone layer
21:35we can still get hit by unhealthy amounts of UV
21:38and that's why it's a good idea to use sunscreen
21:42if you read the label
21:43and if it says broad spectrum
21:45that means it's blocking UVB and UVA
21:48Wow
21:49not UVC
21:50like ozone
21:51but UVA and B
21:54just like we use sunscreen to block harmful UVA and B radiation from our skin
22:00the ozone layer protects planet Earth from harmful UVC radiation
22:05that would destroy the building blocks of life
22:11DNA
22:13without the blocking of UVC by the ozone layer
22:17life would not have been able to come out of those oceans
22:20come up onto land and you and I wouldn't be talking here today
22:24thanks ozone
22:29without that global protection
22:31the grand story of evolution that began from single cell ocean dwelling life
22:37and led to the wondrous complexity of multicellular animals
22:41occupying land sea and sky
22:44would probably never have been told
22:50and yada yada yada
22:52yeah yeah I know
22:54the evolution of life is important
22:56but let's talk about something really important
22:58me
23:01or at least me and my molecules
23:03I know what elements I'm made of
23:06schnapps
23:08carbon
23:09hydrogen
23:10nitrogen
23:11oxygen
23:12phosphorus sulfur
23:13schnapps
23:15there are other elements in the human body
23:17but these are the main six
23:19and of course a good chunk of me by mass
23:23is good old H2O
23:24but if you take that water away
23:27most of what's left
23:30is macromolecules
23:32mostly big long polymers
23:36chains of smaller molecules
23:38yeah so I once went schnapping that's
23:43to learn more about them
23:45biologist Monica Hall Porter
23:46formerly at La Salle University
23:49now at the University of Texas
23:51offers to show me around a local
23:54supermarket
23:56it's kind of weird I ask you about the molecules of my body and you bring us to a grocery store
24:08yeah so today's shopping trip is about the macromolecules that actually make up human body
24:14specifically proteins lipids or fats carbohydrates and nucleic acid and if you take a look around the grocery store there are many examples of those macromolecules here
24:24all right show me the ropes
24:26let's go shopping
24:32our first objective protein molecules
24:36Monica tells me by weight that's about 20% of my body
24:41does that mean pure masculine muscle is that what you're saying
24:45well not necessarily muscle
24:49proteins are the molecules that actually do work in cells
24:53so not just composing muscle but also the proteins that serve as structural proteins in our hair fingernails
25:01the most abundant protein in your body is collagen making up fibrous tissues like skin tendons and ligaments
25:11there's also collagen in teeth and bone
25:15but even though there are tens of thousands of different proteins in the human body
25:20maybe millions
25:23no one is sure
25:25amazingly
25:27they're all made from stringing together about 20 different kinds of small molecules called amino acids
25:33which we get by breaking down the proteins we eat in a variety of foods
25:39and so when we consume protein like in turkey for example
25:43whoa
25:45our body breaks the amino acids down and then the amino acids are incorporated into proteins that our body synthesizes or makes
25:52yeah there you go
25:54handsome little gobbler
25:56next on the macromolecule shopping list
25:59lipids
26:01alright so let's find the lipids aisle
26:02well there's no lipids aisle
26:03but
26:04we can get oils
26:05and fats
26:06so let's head down this way
26:08alright
26:09and let's get some oil
26:10this is massive
26:11how much fats are we getting?
26:13a lot
26:15oh man
26:17this seems like we've got 15 pounds of fats here
26:21and you're telling me that's only half the amount in my body?
26:24absolutely
26:25you're about 30 pounds of fat
26:27now i have to say i find that a little insulting
26:30well you shouldn't
26:33compared to proteins lipids or fats do get a bad rap
26:39but in addition to their role in cell membranes
26:42and long-term energy storage
26:45you know body fat
26:48they also provide protection for internal organs
26:52oh and don't forget the lipids in earwax
26:55and so literally there's fat in every part of you
27:00so even a slim, lean, handsome, physically fit person
27:04could have 30 pounds of fat in them?
27:06absolutely
27:10next up the third most common macromolecule type
27:13oh this is my kind of food group
27:15carbohydrates
27:16sugar
27:17does this count as carbs?
27:19absolutely
27:20while i would have thought i was sweeter
27:23turns out on average there's only about 2 pounds of carbs in me
27:28glucose is the most abundant carb in the human body
27:32it circulates to provide energy for cells
27:35now we're talking carbs
27:38carb city, carb heaven, carb central
27:40we are in the bread aisle my friend
27:42i like it
27:43we can toast this up and put some butter on it
27:45many glucose molecules joined together can make a plant starch
27:50the kind you find in cereals and root vegetables
27:53it's the most common carb in the human diet
27:56so as i understand
27:58hey we're working here
28:00so we've got lipids
28:02yeah protein
28:03yeah and carbohydrates
28:05yeah the three macromolecules of the human body
28:07right but we're missing one
28:09there's another one?
28:10yeah we don't have anything that's representative of nucleic acids
28:12nucleic acids
28:14nucleic acids are better known
28:15as DNA
28:17and RNA
28:19DNA is the famous double helix
28:22it's usually two long chains of molecules that wrap around each other
28:27it contains genetic instructions for making proteins
28:33RNA is often a long molecular chain as well
28:37if DNA is the cookbook
28:40RNA is the chef
28:42reading DNA's instructions for proteins
28:45gathering the ingredient amino acids
28:48and assembling them in the right order
28:50in a macromolecular protein printing machine called a ribosome
28:55life on earth exists in a spectacular variety of forms
29:00but in the end
29:02it all depends on the arrangement
29:04of a handful of different small molecules
29:06the nucleotides
29:08the nucleotides
29:10in the nucleic acids
29:12DNA and RNA
29:14and we are now arriving at the DNA aisle
29:17alrighty
29:19and why strawberries?
29:21well strawberries actually have eight copies of each chromosome per cell
29:24so relative to other fruits strawberries are actually very rich in DNA
29:27wow
29:28alright
29:29here's our DNA e-berries
29:31actually seeing DNA
29:36you know the code of life
29:39has always seemed beyond the reach of ordinary folks
29:43you can't just find some
29:45can you?
29:46when you said we were going to extract DNA from strawberries
29:53I figured we'd go to some humming high-tech lab with millions of dollars of equipment
29:58no actually DNA extraction from strawberries is something that can be achieved at home
30:04as it turns out
30:07using some easily available household items
30:10like plastic bags
30:12detergent
30:14rubbing alcohol
30:16cheesecloth
30:17and strawberries
30:21along with a little bit of waiting time
30:24you too can catch a glimpse of the code of life
30:28DNA
30:33there it is
30:36you'll see an accumulation of white stringy substance
30:41that's actually a very crude prep of DNA
30:48basically what's going to happen is going to clump on the end of your glass rod
30:53strawberry DNA slime right there
30:58pretty amazing
31:00and so are the other three macromolecules that make up my body
31:03but all their wondrous complexity
31:08raises a deeply mysterious question
31:11how did chemistry
31:13give rise to biology?
31:15how did life get its start?
31:21a famous experiment in 1952
31:24suggested the answer might not be that hard to find
31:28at the University of Chicago
31:31graduate student Stanley Miller
31:34with help from his doctoral advisor Harold Urey
31:37mixed what were then thought to be the dominant ingredients of Earth's early atmosphere
31:45methane, ammonia, and hydrogen
31:48inside some sealed glassware
31:50boiling water added water vapor to the mix
31:53then Miller created sparks between electrodes
32:02simulating lightning
32:04and let the mixture cool and condense
32:08after running the experiment for a week
32:11Miller found five amino acids
32:13some of them critical building blocks of proteins
32:19you know it was a dramatic breakthrough at the time
32:22for people to realize that amino acids could be made in such a simple way
32:26at Massachusetts General Hospital
32:30Jack Shostak runs one of the several research labs around the world
32:34that are trying to figure out how chemistry gave rise to biology
32:38so this is like increasing the amount of sodium hydroxide
32:40and so increasing it a bit more
32:43today it's clear
32:45even the Miller-Urey experiment
32:48while groundbreaking
32:50just scratched the surface of the problem
32:52in retrospect
32:54it kind of fooled people into thinking
32:56that the answers might be easier
32:58than it turned out to be
33:00once you've got the right chemicals
33:02then what?
33:03right, right
33:04all the chemicals get together
33:05and start acting like a cell
33:08a key requirement
33:10seems to be a container
33:13all life on earth
33:15from the simplest to the most complex
33:17is made of cells
33:19with outer membranes
33:23so on the road to life
33:25how did that happen?
33:29scientists like Anna Wang
33:31a former post-doc in Jack Shostak's lab
33:32now a professor at UNSW Sydney
33:36have been working with a simple molecule
33:39that is one of the prime suspects
33:41it's also present here
33:44wow
33:48shaped into bars
33:50in a wide variety of colors and scents
33:52smells good in here
33:53smells amazing
33:55at Molly's apothecary outside of Boston
33:57oh, that's wonderful
33:59that's right
34:00soap
34:02soap's interesting
34:04because a soap molecule
34:05is a combination
34:07of two different types of molecules
34:09called polar and nonpolar
34:11for example
34:15water molecules are polar
34:17each one has a concentration of electrons
34:20in one part
34:22making it negative
34:24which leaves another part more positive
34:26that's polarity
34:27and it makes water molecules
34:29want to stick together
34:31each negative part
34:32attracted to another molecules
34:34positive part
34:38an oil molecule
34:40made up of carbon and hydrogen
34:42is an example of a nonpolar molecule
34:45it has an even distribution of electrons
34:48no polarity
34:50and less stickiness between molecules
34:53in fact
34:55polarity is why oil and water
34:56don't mix
34:58the polar water molecules
35:00stick together
35:02keeping the oil molecules at bay
35:04the less dense oil
35:06floats on top
35:10that's also why trying to clean oily grease off your hands
35:13with water alone
35:15doesn't work very well
35:17it actually won't come off
35:18it's super oily
35:20the two just don't interact
35:23and that's where soap molecules come in
35:26they're hybrids
35:28at one end
35:30are some negatively charged
35:31electron rich oxygens
35:33ready to interact with polar molecules
35:35like water
35:37but the rest is a long nonpolar hydrocarbon tail
35:40with no positive or negative charge
35:43it's more comfortable mixing with other nonpolar molecules
35:47like grease
35:49put some soap on your greasy hands
35:52soapy
35:54and the soap's nonpolar tails stick into the grease
35:59while its polar heads act like handles
36:02ready to interact with the water
36:04taking the grease along for the ride
36:07here's another interesting soap fact
36:10drop some soap into water
36:13and the molecules form little balls called micelles
36:17with their water loving polar heads sticking out
36:21and their water hating nonpolar tails sticking in
36:25that naturally occurring little container
36:29has piqued the interest of scientists like Anna
36:31back at the lab
36:35she adds some soap molecules to water
36:38containing short fragments of RNA
36:40they've been tagged with a molecule
36:43that makes them glow
36:45why RNA?
36:47the current scientific consensus is
36:50that a primitive form of RNA
36:52may have been the first molecule with the ability to replicate itself
36:56jump-starting evolution
36:58next stop
37:01now we're going to go look at it under the microscope
37:04the microscope room
37:06where Anna loads up a sample she prepared yesterday
37:10so this is what our soap molecules have self-assembled into overnight
37:14what are they, bubbles?
37:15yeah they're almost like bubbles
37:17and so what we're looking at here is not the soap molecules themselves
37:21but what they've been able to track inside these cell-sized structures
37:25overnight the soap micelles have self-assembled into larger spheres
37:31trapping the fluorescent RNA inside
37:34and if we could zoom into one of them
37:37we'd see that it actually consists of two layers of soap molecules
37:43arranged with the water loving heads toward the inside and outside
37:47and the water hating tails brought together
37:50when you have molecules that have a polar head group and a non-polar tail
37:56but you don't give them any oil to interact with
37:59the oily tails actually want to interact with each other
38:02and so you end up forming these bilayer structures
38:05wait, so these are soap molecules and these are also soap molecules?
38:08yeah
38:10and they like to assemble into this position?
38:12yeah, that's right, so they like to form these really thin envelopes
38:14and you can imagine this structure extending onwards and onwards
38:16and curving around and forming a sphere
38:19and that's what we're seeing here
38:21we're seeing this bilayer structure encapsulating some green dyed RNA molecules
38:26this lipid bilayer structure isn't alive
38:29but it's familiar to biologists
38:32it's similar to the bilayer structure of the membranes
38:36that surround something that is alive
38:38cells
38:40of course those are much more complicated and more stable containers
38:43better at keeping things in or out
38:46though that feature comes at a price
38:49you take the membranes that we have now
38:52they get rid of all of the highly evolved protein machinery
38:55what you're left with is just an inert sac
38:57it can't grow, it can't divide, it can't even get nutrients in and out
39:01that's why in the days of proto-life
39:04less stable membranes built out of simpler molecules like soap
39:08may have been an advantage
39:09Anna shows me an example
39:12so what I'm about to do is I have some soapy water in here
39:16and I'm just going to add it
39:18what happens is those soap molecules start incorporating onto the existing membranes
39:26look at this, look at this, it just split
39:28so they look pretty spherical now but they're starting to wiggle a bit
39:31and all of a sudden it looks like they might melt
39:36cell division
39:38wow, our cells grow and divide because we have something giving instructions
39:44yes
39:46but you're saying that billions of years ago none of that existed
39:49none of that in here, so what we're kind of simulating is a condition where maybe
39:53these protocells have floated somewhere down the stream
39:55and they've come across a pool of excess soap molecules
40:00and these soap molecules can join the membrane and grow it
40:03so I think what it means is that we can still get simple cells to divide by purely physical mechanisms
40:09and that's what we're trying to understand in the field
40:12like how do you get to do things that kind of seem like life and mimic life
40:17but without any biology
40:19in the early days of Earth
40:22soap or similar molecules may have self-assembled into cell-like containers
40:27do they have the bilayer thing already?
40:29they have a bilayer membrane
40:31but Jack Shostak realizes that's just a start
40:34there are many more steps on the road from chemistry to biology
40:38once you've got the right kinds of molecules, which are pretty simple
40:42they can assemble into membranes
40:44but they can't actually start to do anything interesting in terms of like getting more complicated
40:50and being more like more and more advanced life
40:53until you have genetics
40:55you needed hereditary materials, something like RNA or DNA
40:59once you've done that, you have cycles of replication
41:02because that's got to go on inside these protocells
41:05and it's got to happen just by chemistry and physics
41:08because there were no enzymes, there was no evolved machinery, right?
41:11so in a sense the answer has to be simple
41:15and we just have to figure out how it works
41:22scientists like Jack and Anna are searching for the mysterious road
41:26that led not only to life
41:28but to the mechanism that's allowed it to overcome adversity
41:32evolution
41:33today, some scientists wonder
41:41what if we could harness evolution's creative power
41:44to solve some of our own challenges
41:47wow
41:49nature's constantly changing
41:51hi boys
41:53because there's this tremendous effort to survive
41:56if you can harness that power
41:58that innovation
42:00that nature is doing
42:02and direct it in a beneficial way
42:05then we can use that power of innovation to solve
42:08some of our really tough problems
42:11harnessing the innovative power of evolution
42:15is at the heart of the work of chemical engineer
42:18Frances Arnold of Caltech in Pasadena, California
42:21that could be a huge deal in the world
42:24I hope so
42:26and she's used it to engineer new molecules
42:28to solve a wide range of problems
42:31from the search for new antibiotics
42:34for methods to convert waste into biofuels
42:37to teaching cells to bond elements in ways never before seen in nature
42:43so do come if you're interested in the process of protein engineering
42:47engineering
42:48because that's the future
42:50so all of you who are going to do
42:52She's achieved her successes
42:54by discovering new catalysts
42:56the materials that speed up chemical reactions
42:59without getting consumed by them
43:01especially in C-edge functionalization
43:04In living things
43:06catalysts are called enzymes
43:08for example the protein Rubisco
43:10enzymes help facilitate the reactions
43:13that make life possible
43:14The reason that you and I can sit here and talk
43:18is that we have thousands of catalysts in us
43:22proteins that can convert the food we eat
43:25into the thoughts that you think
43:27and the motor mouth, right?
43:29These are catalysts that do all this chemistry
43:32these are chemical transformations
43:34that make life possible
43:36In fact, they work so well
43:39engineers and scientists have wanted to find a way to co-opt the ideas
43:44to create new enzymes that would do our bidding
43:48assisting reactions that aren't found in nature at all
43:51The question is, how?
43:53Many scientists and engineers feel that in order to design a new product
44:01you sit down and you calculate the right angles and the right weights and loads
44:07I come from a different point of view that these very complicated things are the products of evolution
44:14So I say let's just go straight to the answer using this gift given to us
44:24Francis uses an approach called directed evolution
44:27One way to think about directing evolution is it's like breeding
44:34It's like breeding cats or dogs
44:37With a specific end goal in mind
44:42She starts with DNA that encodes for some protein catalysts
44:47that have some promising traits depending on what she's looking for
44:50The DNA gets copied in a way that produces random mutations
44:56She puts that into microorganisms that multiply and produce a variety of slightly different proteins
45:04So you have a gene, the organism reads the gene, makes the proteins
45:09They're all slightly different, just like your children
45:11But now I can decide who goes on to parent the next generation
45:17Because I measure what those proteins do
45:20Francis tests the results to see if any represent a step in the right direction
45:25If so, that becomes the new starting point
45:29And she repeats the process
45:33To see how quickly you can train enzymes
45:37That's what we're doing
45:38We're training them, we're breeding them
45:40To do something that perhaps nature never did before
45:44When you discover that they've learned how to do that
45:48And they do it better than any human can do
45:51It is so exciting
45:55To see how directed evolution can work outside the lab
45:58Farming has always been about increasing productivity
46:01Francis suggested that I contact one of her former students
46:04Pedro Coelho
46:07Along with a partner
46:09She and Pedro founded a company
46:11Provivi, based in Santa Monica
46:14Pedro is the CEO
46:18Provivi makes a chemical to fight this agricultural pest
46:22The fall army worm
46:24It's a pest that is native to the Americas
46:27But in the last three years
46:29It's invaded all of Africa
46:30And now all of Asia
46:32Going from India to China
46:34And it's a very difficult pest to control
46:36Because once it infests the corn
46:39It hides inside the corn plant
46:41Where the insecticides can't touch it
46:46But Provivi's chemical isn't a pesticide
46:49It doesn't kill anything
46:51Instead, it disrupts the way fall army worms mate
46:56Here's how it works
46:58Fall army worms
47:01Eventually become adult moths
47:03And that's when they mate
47:05To attract males
47:07Female moths release a pheromone
47:09A molecule that acts as a chemical signal
47:12So the female moth will release a little bit of pheromone
47:16And then the male will pick up that signal with his antenna
47:20And will fly towards her to mate and reproduce
47:23She uses only a small amount
47:27But it's incredibly potent
47:29It can attract males from up to a mile away
47:33These are complicated molecules
47:36These are the Chanel No. 5 of insects
47:41But such a powerful sex perfume
47:44Can become a means of control
47:46So imagine now you come with a bottle of Chanel No. 5
47:52And you spray it everywhere
47:54Then he can't find her
47:57And they don't mate and have caterpillars
48:00Provivi has figured out how to replicate the fall army pheromone
48:06And put it into a slow release spray for crops
48:11Which you have to imagine is very confusing for the male moths
48:16They have so much trouble finding females
48:19That in the end
48:21There are fewer eggs
48:23And worms
48:25So you're not killing these things
48:27And you're not driving them away
48:28You're just confusing them?
48:30Yes, so it's not a repellent
48:32And it's not a kill agent
48:34It's simply a mating disruptor
48:39Pedro tells me using pheromones to combat pests
48:42Isn't new
48:43But until now
48:46It's been expensive
48:48And therefore limited to high value smaller crops
48:51Like apples or grapes
48:53So the real breakthrough at Provivi isn't using pheromones
48:58But making them inexpensively
49:00They've studied the enzyme catalysts the insect uses to make the pheromone
49:06And moved the genes for those enzyme catalysts into yeast
49:10Then through directed evolution
49:15They optimize those little yeast cell factories for larger scale production
49:20In vessels similar to those used for brewing beer
49:24And the key is that by just changing the micro
49:28We can make many different pheromones
49:30But using the same infrastructure which gives us the economies of scale
49:33Should make this cost effective
49:34Making it possible to use on staple crops grown around the world
49:39Like corn and rice
49:41Our mission very much is to take this proven tool of pheromones to the largest markets of agriculture
49:49Which are the staples of humankind
49:50Companies like Provivi aren't the only sign that directed evolution and cell factories are having a big impact on manufacturing
50:03Well I teach this course called reaction engineering
50:08Which is how do you take chemical reactions and scale them up?
50:12In 2018, Frances Arnold won the Nobel Prize in Chemistry
50:17For her pioneering work in directed evolution
50:21Is this idea of chemistry and biology to manufacture stuff
50:26Is that catching on these days?
50:31It is. It most definitely is
50:33I think the future is so exciting
50:37Because now what happens is with these tools of being able to manipulate DNA
50:43And the code of life really
50:46We can now merge all these beautiful mechanisms of the biological world
50:51With the inventions of human chemistry
50:53And that way it merges in new innovations
51:02That both chemists and biologists have a lot to learn from each other
51:06Should come as no surprise
51:10But what is surprising
51:12Is that biology would arise out of chemistry at all
51:15Look at this, look at this
51:17Cell division
51:19The blueprints of life
51:20The origin of life remains one of the great unsolved mysteries of science
51:26Was the mix of chemicals on early earth destined to give rise to life?
51:32And once it started
51:34Was the road that led to the chemical complexity of photosynthesis
51:38And the harnessing of the power of the sun
51:41Probably the most important process on the planet
51:43The only road to be taken?
51:46Are we alone in the universe?
51:49Or just the local branch of cosmic biochem?
51:54The answers to questions like these
51:58Will be found only through science
52:01As we go beyond the elements
52:04Beyond the elements
52:05Beyond the elements
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52:50The movie is amazing
52:52To order this program on DVD
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52:56Or call 1-800-PLAY-PBS
52:59Episodes of NOVA are available with Passport
53:01NOVA is also available on Amazon Prime Video
53:03This is a production of NOVA's available on Amazon Prime Video
53:09This is a production of NOVA's available on Amazon Prime Video
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