2. 5’
3’
DNA replication starts at the origin of
replication. It is in the shape of a
double helix(twisted ladder).
Key
H
-DNA Helicase
-Phosphate
-Deoxyribose
Nitrogenous bases
C
3’
-Cytosine
G -Guanine
A
-Adenine
T
5’
-Thymine
3. DNA helicase is the enzyme that
unwinds and unzips the double helix
shape. It breaks the hydrogen bonds.
3’
5’
Key
H
-DNA Helicase
-Phosphate
-Deoxyribose
Nitrogenous bases
C
3’
H
-Cytosine
G -Guanine
A
-Adenine
T
5’
-Thymine
12. 5’
DNA polymerase 3 reads the bases 35 and synthesizes 5-3 and it adds
continuously onto the left side. The
nitrogenous bases add to their
complementary bases.
3’
Key
H
-DNA Helicase
-Phosphate
-Deoxyribose
Nitrogenous bases
3’
5’
C
-Cytosine
G -Guanine
A
-Adenine
T
-Thymine
15. 5’
3’
The leading strand which is the left
side and the right side synthesizes
discontinuously with okasoki
fragments. DNA primase adds the
DNA primers to fill the right side.
Key
H
-DNA Helicase
-Phosphate
-Deoxyribose
Nitrogenous bases
3’
5’
C
-Cytosine
G -Guanine
A
-Adenine
T
-Thymine
19. 5’
3’
Polymerase changes the RNA primers
into DNA and DNA ligase seals
everything up with phosphodiester
bonds.
Key
H
-DNA Helicase
-Phosphate
-Deoxyribose
Nitrogenous bases
3’
5’
C
-Cytosine
G -Guanine
A
-Adenine
T
-Thymine
20. When there is an error in DNA replication, it is known as a mutation. The mutations can be the
wrong bases pairing (A-G, A-C, T-G, T-C), or one of the strands of the double helix loops out
such that a bases would be behind two others. Also as the cells divide, the telomeres at the ends
of the genes were down they will either die or cause various problems.