HOMEWORK REVIEW
PROJECTS ARE
– DUE FEBRUARY 23rd
How DNA is Used by the Cell
THE FUNDAMENTAL RELATIONSHIP
Chromosome
Gene
Message
Product
(DNA)
(mRNA)
(protein)
DNA
The Molecular
Basis of Life
GENETIC CODE
the program for the cell
DNA
(de-oxy-ribo-nucleic acid)
a nucleic acid that stores
and transmits the genetic
information from one
generation to the next
aka…. DNA
is the mackdaddy
without DNA we
would have no way to
store genetic
information!!!
The Quest
for the Structure
of DNA
Big Players in DNA
Chargaff
Rosalind
Franklin
Watson and Crick
People knew that DNA
was made up of:
Adenine
(A)
Guanine (G)
Cytosine (C)
Thymine (T)
Erwin Chargaff
• Discovered that in any
sample of DNA, the
amount of A equals the
amount of T and the
amount of C equals the
amount of G.
• This suggested that A
binds with T and that C
binds with G.
Rosalind Franklin’s
X-Ray Crystallography
• Took x-ray photographs
of crystallized DNA
• Discovered that the shape
of DNA must be a helix,
because of the x-ray
pattern
• Died of cancer
(too many x-rays?)
An example of
X-Ray Crystallography
Watson and Crick
• Credited for
discovering the
structure of DNA
in 1953
• Used Chargaff
and Franklin’s
discoveries along
with toy models
to discover the
structure
A 3-D Model of DNA
What Shape is this
called…
Double
Helix!!!
NUCLEOTIDES
Made up of:
A phosphate group (P,O)
5 carbon sugar
Nitrogenous Base
(either A,T,G,C)
The deoxyribose sugar and
phosphate group are identical
in all DNA nucleotides…
nitrogenous bases differ
PURINES
Adenine
(A)
Guanine (G)
PYRIMIDINES
Cytosine
(C)
Thymine (T)
Base Pairing
in DNA
A-T
C-G
Adenine Nucleotide
Cytosine Nucleotide
Guanine Nucleotide
Here’s What a Nucleotide Looks Like
Write the complementary DNA
strand for each of these DNA
strands:
DNA
•
•
•
•
GAATTACA
CCAATTAG
ATAGACAG
CCAGTACA
DNA
•
•
•
•
CTTAATGT
GGTTAATC
TATCTGTC
GGTCATGT
Each of the 96 columns represents one DNA
sequence. A different colored dye attached to
each of the four nucleotides.
Replication
The act of making
an exact copy of
DNA
Semi-Conservative
Replication
Do Not Copy!!
Each strand of the
original molecule acts as
a template for the
synthesis of a new
complementary DNA
With
semi-conservative
replication, each new
strand is ½ new and ½
old
Examples of DNA
Replication
Helicase
is
an enzyme
that unzips
the DNA
molecule
WHAT DO WE KNOW NOW
 We
know how DNA COPIES ITSELF
 Why is this important?
Dolly
5 July 1996
14 February 2003
RNA
(ribo-nucleic acid)
a nucleic acid that is a
messenger between
DNA and the
ribosomes
Differences between DNA and RNA
Different sugars
(DNA=deoxyribose)
(RNA=ribose)
2. RNA is single stranded (1 side)
DNA is double stranded (2sides)
3. RNA has “U” (uracil)
DNA has “T” (thymine)
1.
Always remember…
RNA
loves
U
Write the RNA strand for each of
these DNA strands:
½ Strand of
DNA
•
•
•
•
GAATTACA
CCAATTAG
ATAGACAG
CCAGTACA
RNA
•
•
•
•
CUUAAUGU
GGUUAAUC
UAUCUGUC
GGUCAUGU
Transcription
The process by
which DNA is
copied into mRNA
mRNA
Messenger RNA, is the
copy of the DNA that
goes from the nucleus
to the ribosome….
Translation
The decoding of a
mRNA message
into proteins
Transcription vs Translation
• Messenger RNA is
• DNA goes to
read in the
mRNA
cytoplasm
and
(messenger RNA)
proteins are made
• Takes place in
nucleus
• Done in the
cytoplasm not the
nucleus
 Explain
to your parents in the form of a
letter with pictures how DNA replicates
itself, the process of transcription, and the
process of translation
 Make sure that your parents can
understand what you write and use proper
English
 Graded for Classwork Grade
 Rubric: Daily Assignments Section 5
points


5 = at least 5 sentences with pictures of each
process
3 = middle of the road job with not much effort
FACT
Proteins are
made up of
amino acids
tRNA
Transfer RNA,
matches up with
mRNA and has an
amino acid on its
CODON
Each combination
of 3 nucleotides on
a strand of mRNA
ANTICODON
Each
combination of 3
nucleotides on a
Why is base pairing important?
I WAS MADONNA
I SAW MADONNA
JUST A FLIP OF ONE
LETTER!!!!!!!
 Why
did Mr. Gibney make you
do this?.... Is he just whack??
 Where

is the Mona Lisa?
In the Louvre
In France
 Mona
Lisa = DNA
 Louvre = Nucleus
 Sketch of Painting = mRNA
 Copy on outside = Protein
Assembly
100% Hot Class
Table of Codons
1. What did Willerslev find? Why do you
think this is important?
2. How do the scientists think the DNA got
into the soil?
3. Do you think we can re-create species
from Animal Poop?
4. Think about the last 3 weeks in class and
describe to me how important DNA is.
Jurassic Park Movie Style
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1. Find and collect amber. Amber is tree sap that has hardened and
fossilized also preserving insects inside of it.
2. Take out the mosquito from the amber and extract red blood cells
from its gut (Mosquitos suck blood out of organisms... such as...
DINOSAURS).
3. Extract DNA from the blood cells.
4. Sequence the DNA to create a complete strand of DNA.
5. Fill in any gaps in the DNA by splicing frog DNA with the
dinosaur DNA.
6. Insert this DNA into crocodile ova and create an embryo.
7. Put the embryo inside of special plastic eggs with large yolk sacs
and little water.
8. Incubate the eggs in an environment with 100% humidity and a
temperature of 99 °F.
9. Allow eggs to hatch naturally and for baby dinosaurs to grow.
Jurassic Park: True or Not?

1. Dinosaur DNA is difficult to obtain and to sequence. Although ancient dinosaur DNA has
been found, the DNA is broken apart and must be sequenced. This process is a little difficult
because there is not a complete strand of dinosaur DNA anywhere to copy. We can't simply
make it complete, we have to make sure that every base pair is in the correct place.
2. Even if we have the DNA sequenced, there will be some gaps that must be filled. Unlike in
the movie, these gaps can't be filled by splicing frog DNA. Dinosaur DNA must be used to fill in
the gaps in the DNA. However, we don't have the DNA to do this either. Also, splicing in frog
DNA, will not create a dinosaur, it would create a mutant or a frog/dinosaur type organism.
3. Once the DNA is sequenced and complete, it must be inserted into an oocyte so that it can be
cloned. The oocyte must come from the same organism that is being cloned (in our case this
would be a dinosaur), and since no dinosaurs are alive today, this would be impossible. It
wouldn't work to insert the DNA into crocodile ova because crocodile ova is specialized for
crocodiles, not dinosaurs.
4. Even if crocodile ova could hold dinosaur DNA, a problem still arises with the development
of the dinosaur embryo. Dinosaurs were born through eggs, so we simply can't put them inside
of an organism. We must put them in eggs. In the movie, the scientist created plastic eggs.
However, this would not work because every organism must have a specialized egg. A turtle's egg
will not have the nutrients necessary for a fish, nor would a fish have the nutrients necessary for a
turtle. Every organism must have its own special egg to nourish its young.