End of 12.1 and 12.2
Jul 13, 2015
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)
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
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
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
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
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
DNA replication
occurs during
interphase of the cell
cycle-
There are 3 main
stages to
semiconservative
replication:
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
DNA polymerase adds
the nucleotide bases
to the 3’ end of the
In this way, the
templates allow
identical copies of
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’