DNA REPLICATION
, DEFINITION
• DNA replication is an enzymatic polymerization reactio
which DNA strand is used as a template to synthesize a c
with a base sequence that is complementary to the temp
Replication is semi conservative; each parent single stran
present in one of the double-stranded progeny molecules
, The original Watson-Crick proposal f
• The proposal for the structure of DNA replication of a double-helical molecu
by Watson and Crick in 1953 was
accompanied by a suggested
mechanism for its “self-duplication.”
• The two strands of the double helix are
held together by hydrogen bonds
between the bases.
• Individually, these hydrogen bonds
are weak and readily broken.
• Watson and Crick envisioned that
replication occurred by gradual
separation of the strands of the double
helix, much like the separation of two
halves of a zipper.
, • Semiconservative replication
• Because the two strands are
complementary to each other, each
strand contains the information
required for construction of the other
strand.
• Thus once the strands are
separated, each can act as a
template to direct the synthesis of
the complementary strand and
restore the double-stranded state.
, DEFINITION
• DNA replication is an enzymatic polymerization reactio
which DNA strand is used as a template to synthesize a c
with a base sequence that is complementary to the temp
Replication is semi conservative; each parent single stran
present in one of the double-stranded progeny molecules
, The original Watson-Crick proposal f
• The proposal for the structure of DNA replication of a double-helical molecu
by Watson and Crick in 1953 was
accompanied by a suggested
mechanism for its “self-duplication.”
• The two strands of the double helix are
held together by hydrogen bonds
between the bases.
• Individually, these hydrogen bonds
are weak and readily broken.
• Watson and Crick envisioned that
replication occurred by gradual
separation of the strands of the double
helix, much like the separation of two
halves of a zipper.
, • Semiconservative replication
• Because the two strands are
complementary to each other, each
strand contains the information
required for construction of the other
strand.
• Thus once the strands are
separated, each can act as a
template to direct the synthesis of
the complementary strand and
restore the double-stranded state.
