DNA
Ms. Stewart
October 14, 2014
What does DNA stand for?
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

Deoxyribonucleic Acid
DNA stores genetic information
in the nucleus. DNA is the
genetic blueprint, or recipe, for
making all living things.
Almost every cell in your body
contains DNA, and you have five
trillion (5,000,000,000,000) cells
in your body. THAT’S A LOT
OF DNA!
What does DNA look like?

The shape of DNA is
called the Double
Helix. It looks like a
twisted ladder or a
spiral staircase.

The double helix
twists DNA so that it
fits into the nucleus.
ARE YOU PAYING ATTENTION?
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Where is DNA found?
Nucleus

How is DNA shaped?
Double Helix, Spiral
Staircase, Twisted Ladder

DNA is made up
of Nucleotides.
 To form a DNA
molecule,
thousands of
nucleotides are
joined in a long
chain.

Each Nucleotide has 3
parts:
1. Phosphate group
2. Deoxyribose- sugar
3. Nitrogenous Base
Adenine-A
Thymine-T
Guanine-G
Cytosine-C
What are the 3 parts of a
nucleotide?
What are the 3 parts of a nucleotide?
1. Phosphate group
2. Deoxyribose- sugar
3. Nitrogenous Base
What are the 4 Nitrogenous Bases?
1. Adenine
3. Guanine
2. Thymine
4. Cytosine
Base Pairing
Adenine base pairs
with Thymine (A-T)
Guanine base pairs
with Cytosine (G-C)

The sequence of
these bases
determines all of the
traits of living things.

Bases are paired and held
together by hydrogen bonds
(H-bonds).

What is the complimentary DNA
strand?
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ATGCTTAGCC
_________________
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Purines – have 2 rings
Adenine and Guanine
are purines
Pyrimidines –have one
ring
Cytosine and Thymine
are pyrimidines

Guanine and Cytosine=3
Hydrogen Bonds
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Adenine and Thymine= 2
Hydrogen Bonds
Eukaryotic Cell Structure
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In eukaryotes
(animal and
plant cells) DNA
is found in the
nucleus.
The function of
the nucleus is
to control the
cell’s activities.
Where is DNA
found?
Prokaryotic Cell Structure

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Prokaryotes do not
have a nucleus so the
DNA floats around in
the cytoplasm.
Examples of
prokaryotes are
bacteria.
Chargaff’s Rule

Whenever you see Adenine (A), you will see
________________in DNA.

Whenever you see Guanine (G), you will see
________________ in DNA.

This is also called BASE PAIRING.
Chargaff’s Rule

Whenever you see Adenine (A), you will see
THYMINE (T) in DNA.

Whenever you see Guanine (G), you will see
CYTOSINE (C) in DNA.

This is also called BASE PAIRING.
Replication Animation

http://highered.mcgrawhill.com/sites/0072437316/student_view0/cha
pter14/animations.html#