The twisting tale of DNA - Judith Hauck

Transcriber: tom carter Reviewer: Bedirhan Cinar

Prevoditelj: Ivan Stamenković Recezent: Senzos Osijek

Geckos and grasshoppers, worms and watermelons,

Gušteri i skakavci, crvi i lubenice,

elephants and Escherichia Coli,

slonovi i Escherichia Coli,

man and mushroom. All so different in form and function,

čovjek i gljiva. Svi tako različiti u obliku i funkciji,

but amazingly the same in how their form and function are determined.

ali začuđujuće slični u tome kako su im oblik i funkcija određeni.

First, all these organisms are made of one or more cells,

Prvo, svi ovi organizmi imaju jednu ili više stanica,

and every cell of every living thing on earth

i svaka stanica svakog živog bića na zemlji

contains all the information it takes

sadrži sve informacije potrebne

to create and duplicate and make variations of itself.

da stvori i duplicira te napravi varijacije same sebe.

That information is stored in a very long but quite simple

Te informacije pohranjene su u dugoj

double molecule called DNA,

ali jednostavnoj dvostrukoj molekuli DNK,

or Deoxyribonucleic Acid.

ili Deoksiribonukleinske kiseline.

And the DNA of every living organism is made of chains of four smaller molecules

I DNK svakog živog bića napravljena je od lanca četiri manje molekule

called nucleotides. What dictates the difference between a man and a mushroom

nazvane nukleotide. Ono što diktira razlike između čovjeka i gljive

is the sequence of these nucleotides in the long DNA chain.

je niz ovih nukleotida u dugom DNK lancu.

The four differing nucleotide parts, called bases,

Četiri različita dijela nukleotide, baze,

are made of a few carbon, oxygen, hydrogen, nitrogen and phosphorus atoms,

sastoje se od nekoliko atoma ugljika, kisika, dušika, vodika i fosfora,

and the molecules look like this.

i molekula koje izgledaju ovako.

And each of these four bases is attached to an identical backbone molecule,

Sve četiri baze su povezane na istu osnovnu molekulu,

a sugar called deoxyribose - the "D" in DNA - and a phosphate group.

šećer naziva deoksiriboza - D u DNK - i fosfatne skupine.

Let's simplify these nucleotides and show them like this.

Pojednostavimo ove nukleotide i prikažimo ih ovako.

So, a single sequence of nucleotides joined by their common sugars would look like this.

Dakle, jedan niz nukleotida povezan sa zajedničkim šećerima izgleda ovako.

And the DNA molecule where such sequences are stored looks like this.

I molekula DNK gdje su pohranjeni takvi nizovi izgleda ovako.

But how does a simple molecule dictate the form and function of millions of different living things?

Ali kako jednostavna molekula diktira oblik i funkciju milijuna raznih živih stvari?

You can think of DNA as a great library of information,

Možete DNK promatrati kao veliku knjižnicu informacija,

information that is used to do one thing and one thing only:

informacija koje se koriste isključivo za jednu stvar:

direct the building of different protein molecules.

usmjeravati izgradnju molekula bjelančevina.

And it's the proteins that build the cells and keep them functioning

I bjelančevine grade i održavaju stanice na životu

and changing and reproducing. Here's where the familiar word 'gene' comes in.

mjenjajući se i razmnožavajući. Ovdje u igru ulazi riječ "gen".

If your DNA is a library of information, a gene is a book in that library.

Ako je vaša DNK knjižnica informacija, gen je knjiga u toj knjižnici.

A gene is a segment of the DNA molecule.

Gen je segment DNK molekule.

Let's say your body needs a particular protein, like insulin.

Recimo da vaše tijelo treba određeni protein, kao inzulin.

To get it, some of your cells send a protein signal through the bloodstream

Da bi ga dobili, vaše stanice moraju poslati odgovarajući signal u krvotok

to the cells in your pancreas, where insulin is made.

stanicama u gušterači, gdje se radi inzulin.

That signal protein tells other proteins in the cell's nuclei

Taj signalni protein kaže ostalom proteinu u jezgri stanice

to open up a part of the DNA double helix, the insulin gene,

da otvori dio dvostruke uzvojnice DNK, gena inzulina

and start making insulin proteins.

i počne stvarati inzulinske proteine.

As soon as enough insulin has been produced,

Kada je dovoljno proizvedeno,

another signal protein comes to the pancreas' cells that tells them to stop making insulin.

novi signalni protein dolazi do stanica u gušterači i kaže da prekinu proizvodnju.

It's like looking up a book in the DNA library about insulin,

Kao da tražite knjigu o inzulinu u DNK knjižnici

and then putting it back when you're done.

i onda ju vratite na mjesto kad završite.

There are genes in DNA for visible and invisible things that make up your body,

Postoje geni u DNK za vidljive i nevidljive stvari koje čine naše tijelo,

like genes for eye color, protein pigments, for skin color,

kao geni za boju očiju, proteinski pigmenti za boju kože,

for hair color, for stopping and starting bone growth,

boju kose, za zaustavljanje i pokretanje rasta kostiju,

for your blood type, for how many fingers or arms and legs you have,

za krvnu grupu, broj prstiju, ruku i nogu,

for proteins that influence how long you live.

za proteine koji utječu kako dugo živite.

Your DNA probably contains between 25 thousand and 40 thousand genes,

DNK sadrži između 25 i 40 tisuća gena,

while the DNA of a worm or a plant or a fruit fly

dok DNK crva ili vinske mušice

contains about 12 thousand to 20 thousand genes.

ima od 12 do 20 tisuća gena.

Some of those genes have quite different sequences of nucleotides than yours,

Neki od tih gena imaju drugačije sekvence nukleotida nego vaše

and some are similar to yours.

a neke su slične vašima.

Though it happens infrequently,

Iako se ne događa često,

our own nucleotide sequences can change

naše vlastite sekvence nukleotida mogu se mijenjati

as the result of spontaneous or environmental damage

kao rezultat spontane ili okolišne štete

which might remove or shift a nucleotide position.

koji može maknuti ili pomaknuti poziciju nukleotide.

This changes the gene involved, and can then change the protein.

Ovo mjenja uključeni gen, i onda može promijeniti protein.

Most of these changes, called mutations,

Većina ovih promjena, nazvanih mutacijama,

have very little effect on the organism or its descendants.

ima jako mali utjecaj na organizam ili potomke,

some are mildly damaging,

neki su malo štetni,

and a few can make the organism better-suited to its environment.

a nekoliko ih može promijeniti organizam kako bi bio pogodniji za njih.

It is these tiny changes in DNA gene sequences, happening over millions of years,

Ove male promjene u DNK sekvenciji gena koje se događaju kroz milijune godina,

that create the differences among living organisms, from geckos to grasshoppers.

stvaraju promjene među živim organizmima, od guštera do skakavaca,

worms to watermelons, elephants to Escherichia Coli, and man to mushroom.

crva do lubenica, slonova do Escherichie Coli, i čovjeka do gljive.