Download AMINO ACID CODES (codons)

Double Helix
Helix
unwound
purine
pyrimadine
DNA REPLICATION
is Semi-conservative
Wrong
Two original and two new
complementary strand
Correct
One original and One new
complementary strand
DNA REPLICATION
DNA REPLICATION
It is done with enzymes!
• 1. Helicase (enzyme) unwinds the DNA
– There are now 2 open strands that can be copied
– 2. RNA Primase (polymerase) bring a short, segment
of complementary nucleotides to the new strand
• 3. Then DNA Polymerase (enzyme) brings DNA
nucleotides together to complete a new DNA strand.
• 4. RNA short segment is removed and replaced with
DNa
• 5. DNA Ligase (Enzyme) glues the strands of DNA to
make one continuous strand.
Game DNA Replication
Click here
for Super
challenge
game
DNA
IS MADE
UP OF
IS MADE
UP OF
2 RINGS
THERE
ARE 2
IS MADE UP
OF
ONE RING
THERE ARE 2
1871 Fredrick Miescher
• He isolated a chemical from the nuclueus
of white blood cells.
• What did he call it?
• Nuclein
WALTER SUTTON 1902
“The hereditary material is carried
on chromosomes”
CHROMOSOMES ARE EQUAL
PARTS OF
DNA & PROTEIN
1890’s
SCIENTISTS LEARN THE
SOMETHING ELSE IS …
DNA
FREDERICK GRIFFITH 1928
FREDERICK GRIFFITH
•
•
•
•
DISCOVERED TRANSFORMATION
IT WAS …?
DNA BUT HE CALLED IT?
TRANSFORMING FACTOR
GRIFFITH
• HE WORKS WITH STREP. PNEUMONIA,
A BACTERIA
• 2 FORMS SMOOTH AND ROUGH
• SMOOTH HAS A PROTEIN CAPSULE
THAT CAUSES PNEUMONIA
• ROUGH HAS NO CAPSULE AND IS NOT
DEADLY
GRIFFITH
• 1.HE INJECTS Smooth FORM INTO A
MOUSE
• THE MOUSE…
• DIES
• 2.HE THEN INJECTS THE Rough FORM
INTO A MOUSE
• THE MOUSE
• LIVES
GRIFFITH
•
•
•
•
•
•
•
•
•
3.NEXT HE HEAT KILLS THE Smooth FORM
HE THEN INJECTS INTO A MOUSE
THE MOUSE
LIVES!
4.HE TAKES “KILLED” Smooth & LIVE Rough &
INJECTS THIS INTO A MOUSE
THE MOUSE
CROAKS!
5.HE TAKES A BLOOD SAMPLE FROM THE DEAD
MOUSE AND FINDS
LIVE Smooth encapsulated FORM!
GRIFFITH
• HE SAYS-”SOMETHING
TRANSFORMED THE Live rough FORM
INTO A LIVE Smooth FORM”
• THIS IS SOME KIND OF
“TRANSFORMING FACTOR”
AVERY, McCARTY, MacLEOD
1944
• WANTED TO KNOW WHAT IS THE
TRANSFORMING MATERIAL?
• THEY PURIFIED CHEMICALS FROM
HEAT KILLED “Smooth” bacteria, TO SEE
WHICH ONES WOULD TRANSFORM
LIVE “Rough” bacteria INTO “Smooth”,
deadly bacteria
• THEY DISCOVERED IT WAS DNA
AVERY, ET AL EXPERIMENT
• THEY TREATED SAMPLES OF HEAT KILLED
“S” WITH DIFFERENT ENZYMES TO BREAK
DOWN MOLECULES into rna, dna, proteins,
lipids & carbs.
• TO SEE WHICH ONE CAUSED
TRANSFORMATION
• “R” ONLY BECAME TRANSFORMED INTO “S”,
WHEN IN THE PRESENCE OF…
• Smooth DNA- DID TRANSFORMATION, THEY
FOUND THEIR ANSWER!
Avery et al. experiment
HERSHEY & CHASE 1952
•
•
•
•
WORKED W/BACTERIOPHAGE
VIRUS THAT INFECTS ONLY BACTERIA
ONLY MADE FROM DNA & PROTEIN
THEY CONCLUDED THE INFECTED
BACTERIA WERE TRANSFORMED BY
DNA, NOT PROTEIN
• BUT HOW…
• http://nortonbooks.com/college/biology/ani
mations/ch12a02.htm
HERSHEY & CHASE
Rosalind Franklin
Rosalind’s X-Ray of DNA
Maurice
Wilkins
James Watson &
Francis Crick
1953 WATSON & CRICK
• MAKE THE DISCOVERY THAT DNA IS A
DOUBLE HELIX SHAPE
• THEY WIN?
NOBEL PRIZE
1962 WINNERS ARE
ANNOUNCED
• THEY ARE WATSON, CRICK &?
MAURICE WILKINS!
ROSALIND FRANKLIN
COULD NOT WIN
SHE WAS DEAD!
RNA STRUCTURE
• The sugar is Ribose
• Still has 4 nitrogen
bases
• No Thymine, Uracil
instead
• Still has a phosphate
group
• Single strand
AMINO ACID CODES (codons)
TRIPLET CODE
animation
http://nortonbooks.com/college/biology/animations/ch13a06.htm
• LET’S LOOK AT THE TRIPLET CODE DIAGRAM IN YOUR
PACKET
1st STEP IN PROTEIN SYNTHESIS
TRANSCRIPTION
• DNA UNWINDS USING RNA Polymerase
• __________ BRINGS NITROGEN BASES
THAT ARE COMPLEMENTARY TO DNA
• IT BRINGS SETS OF 3 Nitrogen Bases WHICH
ARE CALLED _______animation
• WHEN THE LENGTH OF MRNA IS COMPLETE
THE MRNA UNATTACHES FROM THE DNA
tRNA STRUCTURE
Carries
Amino Acid
at the Head
Anticodon is
at the base
to match to
the mRNA
codon
Ribosome with tRNA & mRNA
THE 2nd STEP IN MAKING A PROTEIN
TRANSLATION
• 1. The completed mRNA will go to a ribosome in the
cytoplasm
• 2. The codons of mRNA will be read by tRNA
• 3. tRNA will bring 1. a complementary amino acid (LEU/MET
etc.)
• and 2. an anticodon that complements to the mRNA codon to
start building a polypeptide (protein)
ANTICODON
A
C
C
A
A
A
C
C
G
A
G
U
Step 2 TRANSLATION
• There are 3 STOP CODONS, they are UAA, UGA, UAG
• 4. When the tRNA reads them it will stop bringing amino
acids
• 5. When the Protein is complete it can fold up or join
with another protein.
• 6. it will go outside the cell to where it is needed in the
body
• Animation Protein Synthesis
• Build a protein Game
Let’s label the steps!