Download DNA Structure and DNA Replication

DNA Structure and DNA Replication
What DNA is Made of and How DNA Copies Itself
DNA’s Structure
► DNA is made up of _____
corresponding strands each
containing millions of
_____________________.
► Each Nucleotide has a ___Carbon Sugar, a _____________
Group and a _________________
Base.
Nitrogenous Bases
► There are _______
Nitrogenous Bases in
DNA.
► ______________
► ______________
► ______________
► _________________
The Double Helix
► The structure of DNA was
discovered by English scientists,
James ____________ and Francis
_____________.
► They built a model of DNA called
a ____________ __________, in
which _____ strands of DNA are
wrapped around one another
like a ___________ ____________.
DNA Replication
► The process of _______ DNA.
► This occurs during __ Phase
(part of Interphase) of the
Cell Cycle.
► DNA replication is necessary
so that cells have _____
copies of their DNA during
_____________.
► This ensures that each
daughter cell receives an
_________ _________ of the
cells DNA.
► DNA replication follows _____________ Rule.
Chargaff’s Rule
► Erwin Chargaff discovered that the amount of ___________ [A] in
DNA was always __________ to the amount of __________ [T], and
that the amount of ___________ [G] was always ___________ to the
amount of ___________ [C].
► Therefore, he concluded that [A] always ______________ with [T]
and [G] always ________________ with [C].
► This is called Chargaff’s Rule.
Chargaff and Replication
► Due to Chargaff’s discovery, we
now understand why DNA is
able to copy itself without
making _________ or __________
the order of nucleotides.
► This explains why each new cell
is able to always receive an
__________ ________ of the
__________ cells DNA.
How Replication Works
► To begin replication, first the
DNA’s ___________ _________
must unwind and the two
strands must ____________.
► Next, ______ _________________
(an enzyme) moves along each strand of the DNA, adding _______
nucleotides in the proper order.
► In the end, ______ _____ __________ of DNA is bonded with one of
the ___________ strands of DNA, creating two ______________ DNA
double helixes.