Cornell Notes
Essential Questions (Eqs)
1) What is DNA?
2) What is the function and
importance of DNA for all
organisms?
3) What is the basic structure
of DNA?
What is DNA?
DNA: DeoxyriboNucleic
Acid
It is an important biological
molecule (MacroMolecule).
It contains the biological
instructions that make each
species & individual
unique.
Where is DNA Found?
Nearly every cell in a person’s
body has the same DNA.
Most DNA is located in the
cell nucleus (on
chromosomes), but a small amount of
DNA can also be found in the mitochondria.
What is the Function
of DNA?
DNA carries the informational
codes needed for our bodies to
develop and function.
 DNA is the blueprint of life! Without it, we don’t exist.
 This DNA code is copied (replicated) over and over again by our cells.
Blends of genetic codes are also passed down from parents to offspring.
 More than 99% of your DNA is the same as the person sitting next to you. That
less than 1% that is different provides the variation between you and your friend.

What is the Structure of DNA?
 DNA consists of molecules that are arranged
into a ladder-like structure called a Double
Helix.
 A molecule of DNA is made up of millions of
tiny subunits called Nucleotides.
 Each nucleotide consists of:
1. Phosphate group
2. Pentose sugar
3. Nitrogenous base
Draw a Nucleotide:
Phosphate
Nitrogenous
Base
Pentose
Sugar
What forms the backbone of
DNA?
A phosphate and sugar molecule
form the “backbone” of the DNA
molecule, whereas the bases form
the middle steps.
What are the 4 bases?
A
Adenine
C
Cytosine
T
Thymine
G
Guanine
How do the Bases pair?
Each base will only bond with
one other specific base.
 Adenine (A)
 Thymine (T)
 Cytosine (C)
 Guanine (G)
Form a base pair.
Form a base pair.
How can you determine the
sequence of the bases?
The order of the bases in one
strand determines the order
of the bases in the other
strand because they only pair
with one other specific base.
A
T
C
G
T
A
C
G
A
T
G
C
T
A
How do you “read” DNA?
 To crack the genetic code found in
DNA we need to look at the sequence
of bases.
 The bases are arranged in triplets
called codons.
AGG-CTC-AAG-TCC-TAG
TCC-GAG-TTC-AGG-ATC
Why is DNA Important?
DNA is what makes you unique
and alive.
DNA is what tells your cells how
to function.
DNA carries the genetic
information passed from adult
organisms to their offspring.
How does DNA give us our
traits?
 Specific Sections of DNA are called genes.
 A gene is a section of DNA that codes for a
protein.
 Each gene has a unique sequence of bases.
 This unique sequence of bases will code for
the production of a specific protein.
 It is these proteins and combination of
proteins that give organisms their
uniqueness.
DNA
Gene
Protein
Trait
Write a Summary
Following Information:
& Include the
What is DNA & why is it
important (Function)?
Explain what DNA is made of
& draw or describe what DNA
looks like (Structure).
Videos:
Stated Clearly:
 http://www.youtube.com/watch?v=qy8dk5iS1f0
 http://www.youtube.com/watch?v=zwibgNGe4aY
Stated Clearly w Spanish translation
http://www.youtube.com/watch?v=yGJiUUJN_64
Amoeba Sisters:
 http://www.youtube.com/watch?v=_POdWsii7AI