Pages

  • RSS

Saturday, November 7, 2009

DNA

Assalamu3leykum wbt.

kamu tahu?

erk.. alright, i know. This time my entry is supposed to be written in ENGLISH.

i'm writting this with a blanket coiling tightly around me but i'm still shivering in it. oh, forgot to tell you that Jordan has entered its winter time..!! So, let's welcome it. Now, the weather gadget on my lappy screen said it's about 15deg celcius. Also, it's 2.34 a.m. Yeah, i should be in bed right now. But since i have juz woke up from a brief sleep, also because of the effect of caffeine, i can't get on my sleep back. So, to make sure that i use my time wisely i plan to continue reading GENETICS lecture notes which i didn't manage to finish even one of them till now. T.T

ok, let's learn GENETICS with me. I'm now reading bout ermm.. DNA replication.We all know that nucleus has very minute nanometer size while the length of DNA is actually about 2metres long. How could this very long DNA can be put inside the very minute nucleus? Is it simply with crumpling and tangling it without being organised? Nope! Before it is put inside the nucleus, it has been folded in a very perfect way. These are the steps:-
  1. DNA is wrapped around nucleosomes.
  2. Nucleosomes will be supercoiled together around DNA, giving 30 nm filament structure.
  3. This filament sticks to proteins.
  4. Lastly, it will recoil again forming chromosomes as we see under the electron microscope.
DNA replication occurs during cell division in S phase or we call it as synthesising DNA phase.

Now, we'll see the steps of it in sequence.
  1. DNAa proteins recognise the place for initiating the replication.
  2. Once the DNA is opened, DNAb(helicase) and DNAc will bind to DNA helps in the process of opening and unwinding the crumpled DNA.
  3. DNAg(primase) synthesizes primer which is RNA to provide free 3' OH group for DNA synthesis.
  4. DNA polymerase III starts adding deoxyribonucleotides till it reaches the end or next RNA primer. (If it is the continuous, the process of replication is completed here.)
  5. If it is the lagging one, then DNA polymerase I will take over. It will remove RNA primer and add DNA nucleotides at the same time.
  6. DNA ligase seals the gap between the two DNA fragments or we call it as 'Okazaki fragments'.
  7. 2 daughters of new DNA will be formed.
Alright. Finished about the process.

Let's relate it with our daily life. We have seen that DNA is one of the most organised structure. Even though it is actually a very long one it can fit in a minute nucleus. And then after that, it can produce one more of themselves in that condition. Have you ever thought that we can learn from DNA in our lives?

Let's me give an example. And because i'm in the week of exam, i'll give the example on examination. =P

When we are reading books, the first thing is we have to understand what we are reading.
Next, organising. This is the most important part that have to be done. Because, without organizing, the stuffs from the subjects that we have understood will be a mess. And that will make one cannot recall them wisely. How can we relate this with DNA? Look. DNA organises itself with coiling and folding part to make sure that they can recall back their arrangement of nucletides for the process of replication. How awesome it is..!!

That's all from me.

p/s 1: I think this is the second time i wrote about organising. haha.. =.='
p/s 2: Sorry, if you don't understand some terms above. But maybe you can search them on internet. n_n

Wassalam.

7 comments:

Future Murrabi said...

Salam izzah,
winter ke?
walla..
x sempat kite nak merase winter skali ye..
huh..xde rezki..
anyway,
dah lame tak blaja bio,
boleh plak post bende2 ni kat blog..
kite pown nak tulis palas engin dlm blog gak la.

nima said...

Wsalam wbt.
aah. winter.
alaa.. I.Allah, satu hari nanti, syafiqah akan merasa. caiyok2!!

nganganga..
saje post bnde nih. sbb nk apal. hehe..

neway, tulis jelah psl engine. jarang org tulis. tulis ringkas2. senang orang nak paham. keyh, all da bez + pray for us..!!

Kyu Jyushiro said...

Comel la awak ni. Haha. Lame tak jumpa btw.

nima said...

erk..comel??
alamak.. *blushing*

em! lama2.. satu uni tp x terjumpe. kak qisti mnyorok mne eh? =P

ikram-zidane said...

entry paling bosan kat dunia...

nima said...

erk..
sesedap rasa jek eh..

ske atila nk tulis ape.
this is my territory.
sekian, hehe.

Anonymous said...

c0mel??

ek3.. tgkla adek dy sape~