Zusammenfassung der Ressource
Th2L02 DNA replication
- Part of the cell cycle
- G1 phase
- Synthesis of protein components
necessary to complete the cell cycle
including histones, enzymes for
replication, etc.
- Takes 6-9 hours
- S phase:
- DNA synthesis commences
- Overview
- (1) DNA unwinds
- (2) Daughter strands of DNA produced from
parent strand at replication for
- Semi conservation replication (each new DNA
molecule contains one parent and one daughter
strand)
- Overall structure of the replication fork
- Replication occurs 3' to 5'
along parent strand
- Leading strand
- The new continuous complementary DNA
strand synthesised along the template
strand in the mandatory 5' to 3' direction.
- Lagging strand
- A discontinuously synthesised DNA strand that
elongates by means of Okazaki fragment
- Okazaki fragments
- Small fragments of DNA produced on the
lagging strand during DNA replication
- Joined later by DNA ligase
to form a complete
strand
- Each synthesised in a 5' to 3' direction away
from the replication fork.
- New daughter
strand is
formed 5' to 3'
- One leading strand and one
lagging strand
- Several enzymes are involved including helicase, DNA polymerase, primase,
DNA ligase, etc.
- Takes 8-9 hours