1. End of 12.1 and 12.2

2.  Nucleotides are made
up of 3 things:
1. 5 carbon sugar
2. Nitrogenous
(containing nitrogen)
bases
3. Phosphate group
 Nucleic
Acids (like
DNA and RNA)

3.  The nucleic acid DNA consists of the
following:
1. Deoxyribose- sugar
2. A phosphate group
3. A series of 4 nitrogenous bases: cytosine, adenine, thymine,
guanine

4.  The nucleic acid RNA
consists of the
following:
1. Ribose- sugar
2. A phosphate group
3. A series of 4
nitrogenous bases:
adenine, uracil,
guanine, cytosine

5.  Adenineand Guanine
are considered purine

6.  Thymine, Cytosine,
and Uracil are
considered
pyrimidines

7.  DNA is compared to a
twisted ladder
 Ladder Rails- consist of
alternating deoxyribose
(sugar) and phosphate
group
 A purine base always
bonds with pyrimidine
 Bases are held together
by hydorgen bonds

8.  The direction or
orientation of the
 The carbon in the sugar
molecules are
numbered
 The leading strand
starts with the 3’ (five
prime) end
 The lagging strand runs
in the reverse direction
 This orientation of the

9.  Length of a human
chromosome ranges
from
 If a DNA strand 140
million nucleotides
long
 In order for all of the
DNA to fit into
microscopic cells, the

10.  The phosphate
groups in DNA create
a negative charge
 The structure of DNA
wound around

11.  DNA replication is
considered
semiconservative
replication- because
this process consists

12.  DNA replication
occurs during
interphase of the cell
cycle-
 There are 3 main
stages to
semiconservative
replication:

13.  Helicase-is an
enzyme used to
 When DNA is
unzipped, the
hydrogen bonds
between the bases

14.  DNA polymerase-
enzyme that catalyzes
the addition of
appropriate nucleotides
 There are a plethora of
nucleotides floating in
the cell waiting to be
 DNA polymerase
ensures that each base
binds to its compliment

15.  DNA polymerase adds
the nucleotide bases
to the 3’ end of the
 In this way, the
templates allow
identical copies of

16.  The leading strand is
replicated from 3’ to 5’
end
 The lagging strand is
synthesized
discontinously in
segments called
Okazaki fragments by
the DNA
 The lagging strand is
oriented in the 5’ to 3’

17.  DNA ligase- is an
enzyme that connects
all the fragments of