dna replication

assalamualaikum w.b.t...

juz a simple note for my exam ..

dekat initiation,helicase break d hydrogen bond..then,akn ad 2strands yg t'hasil 

-leading,lagging..kt leading,utk bt proses elongation,juz need DNA polymerase,RNA primer wujud kejap je..sbb die continuous reaction..proses elongation kat leading akn continue without more RNA primer..but utk lagging,p'lukan dua2 utk continue elongation tu..bila smpai mse RNA primer abis,akn ad RNA primer len dtg..smpai hbs proses elongation tu n hasilkan okazaki fragment..sbb die non-continuous reaction..okazaki fragment dicantumkn oleh DNA ligase..after sume2 tu,akn ad 2 strands t'hasil iaitu leading ngan lagging..proses replication akn stop bila dua2 da smpai kt ujung strand (kwsn nme telomere)

--> in the DNA replication process,there's three steps involve,  

1)initiation

    - the enzyme helicase will break the hydrogen bonds between the base pairs..the unwinding process happen in the segments that rich in adenin and thymine (A & T)

    - then,the replication fork formed

 

2)elongation

    - there will involved two strands which is leading (5' - 3') and lagging (3' - 5'). in the leading strands,the its only need the DNA polymerase to complete the elongation process because it is a continuous reaction. 

    - but for the lagging strands, it will need both DNA polymerase and RNA primer to complete the elongation process because it is a non-continuous reaction..

    - after that,the Okazaki Fragment is formed. the DNA ligase is needed to bind the Okazaki Fragment together..

 

3)termination 

    - when the DNA polymerase reached the end of the strands,the termination occur at the telomere, the non-coding segments..termination is d last process of DNA replication..



xoxo,

yanie