DNA: The book of you - Joe Hanson

DNK: Knjiga o vama - Džo Henson (Joe Hanson)

Transcriber: Andrea McDonough Reviewer: Bedirhan Cinar

Prevodilac: Jelena Jaranović Lektor: Tatjana Jevdjic

Every human being starts out the same way:

Svako ljudsko biće nastaje na isti način:

two cells, one from each parent,

dve ćelije,

po jedna od svakog roditelja,

found each other and became one.

pronađu jedna drugu i postanu jedna.

And that one cell reproduced itself,

A onda se ta ćelija reprodukovala,

dividing, dividing and dividing

deleći se

i deleći

i deleći

until there were 10 trillion of them.

sve dok ih ne bude 10 biliona.

Do you realize there's more cells in one person's body

Shvatate li da je u ljudskom telu više ćelija

nego što je zvezda u Mlečnom putu?

than there are stars in the Milky Way?

But those 10 trillion cells aren't just sitting there in a big pile.

Ali tih 10 biliona ćelija ne stoje tamo na gomili.

That would make for a pretty boring human being!

Tako bi nastalo prilično dosadno ljudsko biće!

So what is it that says a nose is a nose,

Dakle, šta to određuje nos kao nos

and toes is toes?

i nožne prste da budu nožni prsti?

What is it that says this is bone

Šta je to što kaže: ovo je kost,

and this is brain

ovo je mozak,

and this is heart

ovo je srce,

and this is that little thing in the back of your throat

a ovo je ona mala stvar u dnu vašeg grla

kojoj nikako da zapamtite ime?

you can never remember the name of?

Sve što jeste i od čega ćete ikada biti napravljeni

Everything you are or ever will be made of

počinje kao malo uputstvo

starts as a tiny book of instructions

koja se nalazi u svakoj pojedinačnoj ćeliji.

found in each and every cell.

Every time your body wants to make something,

Svaki put kada vaše telo želi da napravi nešto,

vraća se knjizi sa uputstvima,

it goes back to the instruction book,

pogleda u nju i sastavi šta treba.

looks it up and puts it together.

So how does one cell hold all that information?

Pa, kako jedna ćelija može da sadrži sve te informacije?

Let's get small.

Hajde da se smanjimo.

I mean, really small -- smaller than the tip of a sewing needle.

Ali, stvarno smanjimo,

da postanemo manji od vrha igle.

Then we can take a journey inside a single cell

Onda možemo zakoračiti u ćeliju

to find out what makes up the book of you,

i saznati šta čini vašu knjigu uputstava,

your genome.

vaš genom.

The first thing we see is that the whole genome, all your DNA,

Prvo primećujemo da se ceo genom,

sav vaš DNK,

is contained inside its own tiny compartment,

nalazi unutar svog malog skladišta,

called the nucleus.

koje se zove jedro.

If we stretched out all the DNA in this one cell into a single thread,

Ako bismo rastegli sav DNK iz ove ćelije

u jednu nit,

ona bi bila dugačka oko jednog metra!

it would be over 3 feet long!

We have to make it fit in a tiny compartment

Mi treba da ga spakujemo u mali odeljak

koji je milion puta manji.

that's a million times smaller.

We could just bunch it up like Christmas lights,

Mogli bismo samo da ih nagomilamo kao božićne svetiljke,

but that could get messy.

ali bi tako nastao nered.

We need some organization.

Malo treba da se organizujemo.

First, the long thread of DNA wraps around proteins

Prvo, dugačka nit DNK se obavija oko proteina

clustered into little beads called nucleosomes,

grupisanih u male kuglice koji se zovu nukleozomi,

which end up looking like a long, beaded necklace.

koji na kraju izgledaju kao dugačka niska perlica.

And that necklace is wrapped up in its own spiral,

Ta ogrlica je uvijena u sopstvenu spiralu

poput starog telefonskog kabla.

like an old telephone cord.

And those spirals get layered on top of one another

I te spirale se slažu jedna na drugu

until we get a neat little shape that fits inside the nucleus.

dok ne dobijemo savršen mali oblik koji staje u jedro.

Voilà! Three feet of DNA squeezed into a tiny compartment.

Vau! Skoro ceo metar DNK se ugura u tako mali prostor.

If only we could hire DNA to pack our suitcases!

Kad bismo bar mogli da unajmimo DNK da pakuje naše kofere!

Each tiny mass of DNA is called a chromosome.

Svaki malecki deo DNK zove se hromozom.

The book of you would have 46 chapters,

Knjiga svakog od vas imala bi 46 poglavlja,

one for each chromosome.

po jedno za svaki hromozom.

Twenty-three chapters of your book came from your mom,

23 poglavlja vaše knjige dolaze od mame

and 23 chapters came from your dad.

i 23 poglavlja od tate.

Two of those chapters, called "X" and "Y,"

Dva od ovih poglavlja koja se zovu "X" i "Y",

determine if you're male, "XY,"

određuju da li ste dečak, "XY"

or female, "XX."

ili devojčica, "XX".

Sastavimo ova poglavlja i dobijamo dva gotovo identična,

Put them together, and we get

two almost identical but slightly different sets of 23 chapters.

ali ipak malo različita skupa od po 23 poglavlja.

The tiny variations are what makes each person different.

Male varijacije su ono što čini svaku osobu drugačijom.

It's estimated that all the chapters together

Procenjeno je da sva poglavlja zajedno

hold about 20,000 individual instructions, called genes.

sadrže oko 20.000 uputstava, koja se zovu geni.

Written out, all those 20,000 instructions

Ako bismo ispisali ovih 20.000 uputstava

are 30 million letters long!

trebalo bi nam 30 miliona slova!

If someone were writing one letter per second,

Ako bi neki pisali po slovo u sekundi

trajalo bi gotovo celu godinu da ispišu sve.

it would take them almost an entire year to write it once.

Međutim, ispostavilo se da je knjiga naših gena mnogo, mnogo duža

It turns out that our genome book is much, much longer

than just those 30 million letters --

od tih 30 miliona slova,

almost 100 times longer!

gotovo 100 puta duža!

What are all those extra pages for?

Čemu služe sve te dodatne strane?

Well, each page of instructions has a few pages of nonsense inserted

Pa, svaka strana uputstava ima po par beskorisnih strana

koje moraju da se izvade dok ne dobijemo nešto upotrebljivo.

that have to be taken out before we end up with something useful.

The parts we throw out, we call introns.

Deo koji bacamo zovemo introni.

The instructions we keep, we call exons.

Uputstvo koje zadržavamo, zovemo eksoni.

We can also have hundreds of pages in between each gene.

Između dva gena možemo da imamo stotine stranica.

Neke od ovih suvišnih strana su ubacile

Some of these excess pages were inserted

male gadne infekcije naših predaka,

by nasty little infections in our ancestors,

but some of them are actually helpful.

ali neke od njih su zapravo i korisne.

They protect the ends of each chapter from being damaged,

One štite kraj svakog poglavlja od oštećenja

or some help our cells find a particular thing they're looking for,

ili pomažu našim ćelijama da pronađu neku konkretnu stvar

or give a cell a signal to stop making something.

ili daju znak ćeliji da prestane sa pravljenjem nečega.

All in all, for every page of instructions,

Sve u svemu, na svaku stranu uputstava

there's almost 100 pages of filler.

dolazi 100 "praznih" strana.

In the end, each of our books' 46 chapters

Na kraju, svako od ovih 46 poglavlja

sadrži između 48 i 250 miliona slova.

is between 48 and 250 million letters long.

That's 3.2 billion letters total!

To je ukupno 3,2 milijarde!

To type all that copy,

Da prekucate sve to, trebalo bi vam preko 100 godina,

you'd be at it for over 100 years,

a knjiga bi imala preko 600.000 strana.

and the book would be over 600,000 pages long.

Every type of cell carries the same book,

Svaki tip ćelije nosi ovu knjigu u sebi,

but each has a set of bookmarks

ali u svakoj je obeležen tačno onaj deo knjige

that tell it exactly which pages it needs to look up.

koji treba da pogleda.

So a bone cell reads only the set of instructions it needs to become bone.

Tako ćelija kosti čita samo ona uputstva koja su joj potrebna da postane kost.

Ćelije mozga,

Your brain cells,

they read the set that tells them how to become brain.

čitaju samo uputstva koja im kazuju kako da postanu mozak.

If some cells suddenly decide to start reading other instructions,

Ako neka ćelija iznenada odluči da čita druga uputstva,

može se promeniti iz jednog tipa ćelije u drugi.

they can actually change from one type to another.

So every little cell in your body is holding on to an amazing book,

Dakle, svaka ćelija u vašem organizmu u sebi ima ovu čudesnu knjigu

full of the instructions for life.

punu uputstava za život.

Your nose reads nose pages,

Vaš nos čita stranice o nosu,

your toes read toes pages.

vaši prsti na nogama čitaju svoje strane,

And that little thing in the back of your throat?

a ta mala stvar u dnu vašeg grla

It's got its own pages, too.

takođe ima svoje strane.

They're under "uvula."

One se nalaze u delu: uvula.