Download DNA Replication

Which of the following is a nucleotide
found in DNA?
a. ribose + phosphate group +
thymine
b. ribose + phosphate group + uracil
c. deoxyribose + phosphate group +
uracil
d. deoxyribose + phosphate group +
cytosine
Which of the following is a nucleotide
found in DNA?
a. ribose + phosphate group +
thymine
b. ribose + phosphate group + uracil
c. deoxyribose + phosphate group +
uracil
d. deoxyribose + phosphate group +
cytosine
Figure 12–1 shows the
structure of a(an)
a.DNA molecule.
b.RNA molecule.
c.amino acid.
d.protein.
Figure 12–1 shows the
structure of a(an)
a.DNA molecule.
b.RNA molecule.
c.amino acid.
d.protein.
 Deoxyribonucleic
 DNA
 All
Acid
is the molecule involved in inheritance.
the genetic information (instructions)
that are used to build your body.
 Nucleotides
are the monomers of nucleic
acids.
 Nucleotides are made of: 5 carbon sugar,
phosphate group, and a nitrogenous base
4
Nitrogenous
Bases:
Adenine (A)
 Thymine (T)
 Guanine (G)
 Cytosine (C)

Pyrimidines- single
rings
Purines- double rings
 Adenine
pairs with
Thymine (A-T)
 Cytosine
pairs with
Guanine (C-G)
 Shaped
like a
double helix
 DNA is compared to
a twisted ladder!
 The steps of the
ladder are the
paired bases.
 The rails are sugars
and phosphates that
alternate.
 Let’s
extract DNA from some common fruits
that we eat so we can see.
You will be given an
“template Stand,
create the
complementary
strand .
DNA
Coloring:
Handout
DNA
History
Webquest
 Parent
strands of
DNA separate and
serve as the
template for the
new DNA.
 Each DNA molecule
has a parent strand
and a new one!
 Occurs during
interphase of
mitosis and meiosis.
 DNA
strands run
“antiparallel” to
one another.
 The 5’ (five prime)
end has a
phosphate group.
 The 3’ (three
prime) end has a
sugar.
 HELICASE
unwinds
a segment of DNA
 It
“unzips” the
double helix
 RNA
Primase attaches to the DNA and
synthesizes many short RNA primers
 DNA
Polymerase III
adds new
nucleotides to the
3’ end of the RNA
primer
 Leading

Synthesized continuously from 5’ to 3’
 Lagging

Strand
Strand (Okazaki fragments)
Since DNA Polymerase III can only add new
nucleotides to the 3’ end of the primer, this
strand is synthesized DIScontinuously
 DNA
Polymerase I will then remove the RNA
primers and replace them with DNA
nucleotides
 DNA
Ligase is a “linking” enzyme that seals
the Okazaki fragments together
 http://highered.mcgraw-
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