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[Music]

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[Applause]

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thank you guys for coming thanks for

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inviting me you guys I'd like to

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announce that the next apps icon is

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going to be at Georgia Tech and it's

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gonna save us a lot of money and air

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fares and hotels these are all the

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Georgia Tech people at this meeting or a

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okay I'm gonna talk about biopolymers

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and you guys my time doesn't start yet

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because it's kind of background

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information the the this this new

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mission

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you know the dragonfly this is like so

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good for us right this is we're going to

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a planet with polymers and organic

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chemistry this is going to be really

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exciting for all of us here okay so I

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want to talk about polymers you know

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like does biology actually need polymers

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and our biopolymers special among

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polymers and what can we learn about

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biopolymers you know about the origin of

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life what do biopolymers actually tell

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us about the origin of life and when you

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think about biopolymers of course this

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is sort of where we start which is

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really you know this is information flow

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in biology right there's sequences of

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DNA that's information is is transcribed

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to RNA it's translated to protein and

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then protein actually does things with

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that information so this is all about

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information and information is sequences

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of monomers that are linked that's

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really essentially what polymers are

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about so isn't it really important to me

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feature polymers is that they are all

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made by dehydration condensation okay

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everybody Universal bio polymer is made

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by essentially the same chemistry which

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is you take two monomers you put them

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together and a water molecule comes out

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and there's a lot of other things that

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are universal they all go through

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phosphorylated intermediates they're all

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made by possessives motors that use

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divalent cations there's a there's a

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whole lot of universalities in bio

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polymer synthesis but i want to focus on

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this water element here this is the way

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i think about it which i think you

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should think about it which is that you

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know I'm at AB

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is a small molecule that is either used

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as a substrate or a product in an

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enzymatic reaction and water is clearly

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the most abundant and frequent and

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universal metabolite in all biology you

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use over your body mass of water in

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chemical reactions every day so water is

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the primary metabolite of biology what

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does that mean if we think about the

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surface of the land now I'm talking

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about NIC HUD kind of ideas here that's

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so where they come from is the activity

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of water on so on the entire planet

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cycles every day so reactions that take

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up and and release water are pushed and

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pulled on the entire planet every day

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except in certain places and that's in

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large bodies of water that is that that

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is a place where the activity of water

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is constant and and we're not going to

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be able to push in pull reactions by

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this process so the abiotic synthesis of

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polymers by the cycling of water is a

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metabolic process and think about what

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Moran was saying if you were here for

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her talk early you take monomers you dry

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them down you make polymers and you

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bring them back up into solution and

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there kinetically trapped so what you've

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done is you've taken sunlight

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effectively and you have incorporated

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that energy into chemical bonds okay so

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that that is basically what the dry down

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root reaction does it's taking

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environmental energy and it's putting it

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into chemical bonds and you repeat this

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process and you can keep adding more and

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more energy into chemical bonds okay so

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this is this is metabolism to me and

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it's it's kind of funny I remember in

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the old days Steve and people would have

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these arguments about what was first

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nucleic acids or or metabolism and the

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problem with those discussions I think

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was that the way people were thinking

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about metabolism was in terms of the

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krebs cycle running in Reverse and

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things like that but if you think about

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metabolism in this way I think it

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changes the argument I think Steve might

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haven't talked to him about this but I

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think he might accept that metabolism

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could take a lead before biopolymers if

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we define metabolism like this

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you don't have to say anything I'll ask

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you later over beers okay so now let's

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talk about actually it's kind of ironic

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that the people who finally discovered

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this metabolic process where nucleic

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acid people they were naked and and ROM

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Krishnamurti and people like that so

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that the people who are focused on

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metabolism are really interested in the

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Krebs cycle and redox chemistry and

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things like that

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and they really weren't paying attention

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to simple chemistry which is hydration

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dehydration which is near equilibrium

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processes on the surface of the earth so

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if we look there then we can see that

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it's really easy to imagine metabolism

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and biopolymers you know coming together

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okay so this is a polymer polymers are

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amazing they're magic okay polymers are

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magic that's the thing you have to

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realize they're undescribable amazing so

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if you look inside those things what you

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can see this beautiful self

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complementarity all biopolymers our self

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complimentary if you look at cellulose

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all the donors donate and all the

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acceptors except if you look in the

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center of a protein the donors and

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acceptors are beautifully aligned and of

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course if you look in nucleic acids

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nucleic acid chemists are used to

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talking about complementarity but that

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complementarity extends to all

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biopolymers okay every biopolymer is

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itself complementary you can see a Alpha

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anti parallel beta sheets and parallel

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beta sheets and alpha helixes everything

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is beautiful everything is perfect okay

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the problem is the same thing is true in

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ice if we take a water molecule and we

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crystallize that you look in that

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crystal you'll see the same thing small

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molecules when they form crystals are

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also self complimentary all the donors

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donate and all the acceptors accept so

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the question is really what what is

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special about a polymer how is that how

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is an Ice Cube different from a polymer

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what is the fundamental difference

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okay this is this is the difference if I

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take I say I take a mixture of 20 amino

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acids and I very slowly cool it they

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will resolve okay this is called

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recrystallization people make money off

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of this right this is how you purify

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things you recrystallize them because

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monomers will resolve in two simple

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systems biology doesn't want that right

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biology wants enzymes informational

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molecules it wants to

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it wants to through evolutionary process

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put functional groups at specific places

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in three-dimensional space okay that is

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not allowed here everything is

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determined by this small molecule so

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there there's no control of that that

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biology requires so we want to do this

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but nature doesn't let us do that okay

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if I take 20 amino acids and I try to

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assemble them I can't do it if I take

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guanine and cytosine together in water

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they don't form base pairs unless

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they're polymerized okay the magic is in

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the polymerization so this doesn't work

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but this works okay with linking things

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together and the linkage is really

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important okay it does it two things

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first there's the proximity it keeps

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things close together so the entropy is

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much less forming this thing because

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these things are already constrained to

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be close together in space so there's a

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big entropy argument but the other thing

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is this you know in biopolymers these

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are not flexible strings right these are

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very specific for example a peptide

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highly restrained pre-organized and and

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really already pushing very hard for

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this assemble thing in fact any RNA you

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make any sequence of RNA except for a

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homo polymer and it will assemble right

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RNA just wants to assemble so bad you

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can't stop it and any sequence of

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polypeptide will form beta structures

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right so the assembly of these molecules

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is built into the backbone in many ways

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and it's just totally inescapable um

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people complain that they make random

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sequences of polypeptide and it always

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comes out of solution the reason is that

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it forms beautiful beta structures right

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those aren't just random precipitates

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right those are those are assemblies

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that have been designed by Nature over

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long evolution how much time do I got oh

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okay good so we talked about proteins

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spontaneously folding right you take a

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protein in solution and it will

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spontaneously fold but the only reason

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for that is that you're cheating on the

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accounting if you really add everything

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up like how much did it cost to make the

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amino acids how much did you invest in

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selecting for the right sequence and

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then of course for making the bonds in

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an aqueous media proteins do not

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spontaneously fold right they only

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spontaneously fold is because you're

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starting with the polymer okay so and

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that's kind of cheating

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thermodynamically so this is I think the

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way to think about it

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this is what nature can do really easily

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and what nature has done is it has

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separated the cost of the assembly

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Nature wants complex assemblies it wants

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informational biopolymers it wants

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catalytic sites and it has separated the

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cost of that assembly from the making of

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the assembly so the sequence of this

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thing and the backbone has been designed

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by billions of years of evolution right

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that is an investment that Nature has

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made in this polymer it has selected the

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side chains it has selected the sequence

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and then what it actually does the

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polymerization of course it uses ATP and

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high-blood so there's an enormous amount

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of energy that is put and the reason

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that energy is invested is in order to

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make assemblies and so this is this is

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the analogy I use money if you don't

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have to pay for stuff you can have

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everything right and that's what Nature

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has done it has invested so much in the

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past that assemblies are free and so the

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way to think about it is if you have

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saved your whole life for your kid to go

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to college then you can send your

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college to your kid to college

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essentially free because you have that

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account and you're not you don't have to

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pay for it in real time

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that's what biology has done biology has

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been investing in in assemblies for

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billions of years

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and has made them spontaneous and it and

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free right this is why nature does such

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crazy things because it really doesn't

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have to pay for it right it's it's

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already paid that investment is a done

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deal and and everything it wants to do

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is essentially free so thank you guys

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this is my group and actually I have

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this is Moran who has done a lot of work

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on the DEP c-peptide stuff this is Anton

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who talks to me about these things all

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the time

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and the other member of my group are

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here thank you guys okay we can only do

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one quick one because I've been informed

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that we have another group coming in

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right after us okay so yeah usually

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disagree with Lawrence I hope you're

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going does he didn't say anything about

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human beings so it's I thought an

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interesting idea about the water

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activity being like the first metabolism

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when I talked to RNA world people they

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usually don't talk about metabolism in

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that world so you but you need some type

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of energy to replicate yourself so is

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that is water activity variation a

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candidate for the metabolism in an RNA

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world I would say no because RNA is so

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far from equilibrium that these

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processes in fact I would say RNA is a

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very derived polymer that comes from a

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lot of chemical evolution or if you look

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at peptides and sugars and other things

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you polymerize

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you can do them near equilibrium by

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dehydration it's very simple RNA because

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it's so far from equilibrium with that

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phosphate that's the only polymer that

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it doesn't work so I would I would argue

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based on that and some other things that

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already has a very derived polymer and

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it of the polymers we have it's the one

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that is farthest away from the sort of

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origins of chemical evolution alright