RNA and Protein synthesis

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Transcript RNA and Protein synthesis

SIT DOWN AND
PREPARE THY SELF!!!!
…PAPER AND PENCIL
WOULD ALSO BE NICE

COMPETITION TIME!
• 1.) Which amino acids correspond with the following
Anti-codons?
UAG AAU AUC CCG GGG UGA
• 2.) Write two codon sequence possibilities for the
following amino acid chain.
Serine-valine-alanine-glycine-leucine-STOP
3.) Take your codon sequence from problem 2, replace
all A’s with U’s and all G’s with A’s: write the new amino
acid sequence.
RNA AND PROTEIN
SYNTHESIS
MR. NICHOLS
PHHS
TIME TO ACT!
• Group 1: Creation of mRNA including transcription
factors.
• Group 2: How tRNA binds with a particular amino acid.
• Group 3: How the ribosome works to create a protein.
• Group 4: What happens once the stop codon is read.
• Group 5: Examples of what proteins are used for and
what happens to them once they’re done being used.
EVEN MORE DETAIL
SUMMARY
• tRNA synthetase grabs the tRNA and appropriate
amino acid and links them together by using the
energy of an ATP molecule.
• Once the ATP’s energy is used to create a high
energy bond the tRNA and amino acid are
released and then travels to the ribosome.
• Video 
A LITTLE MORE DETAIL!
• A Transcription factor is a protein that binds to
specific DNA sequences, thereby controlling the of
genetic information from DNA to mRNA.
Transcription factors perform this function alone or
with other proteins in a complex, by promoting (as
an activator), or blocking (as a repressor) the
recruitment of RNA polymerase.
• -Upregulation, activation, or promotion – increase
the rate of gene transcription.
• -Downregulation, repression, or suppression –
decrease the rate of gene transcription.
EVEN MORE 
Coactivator – a protein that works with transcription factors to increase
the rate of gene transcription.
Corepressor– a protein that works with transcription factors to decrease
the rate of gene transcription by blocking the binding of RNA polymerase
to DNA
Common Transcription Factors associated with diseases:
MECP2- Rett’s Syndrome
MODY- Diabetes
FOXP3- Autoimmune Diseases (I study this one )
STAT- Breast Cancers
HOX- Multiple Cancers
THE “CENTRAL DOGMA THEORY”
• DNA provides the code on how to construct RNA and
RNA provides the code on how to create proteins.
• Created by Francis Crick in 1959.
• This theory is the basis for how proteins are created
and the role DNA plays in the process.
WHERE DO WE START?
RNA
DNA
STEP ONE: TRANSCRIPTION
1. DNA unzips: Helicase splits apart base pairs
and unwind the DNA double helix.
2. Bases pair up: Free nucleotides in the cell
find their complementary bases along the
new strands with the help of RNA
polymerase.
3. New backbone formed: The sugarphosphate backbone is assembled to
complete the RNA strand, and separates
from the DNA strand.
WHAT DOES THIS LOOK LIKE?
Gene: A region of DNA that codes
for a protein.
WHAT DOES THIS LOOK LIKE?
WHAT DOES THIS LOOK LIKE?
mRNA
This process is called Transcription!!!
TRY IT OUT!
• Try it! What RNA strand will be made from the
following DNA sequence?
GET IT RIGHT?
• Try it! What RNA strand will be made from the
following DNA sequence?
AUGCGUACUGAUCGUUCAGAUUGA
SUMMARY:
HOW TO CREATE RNA FROM DNA
• RNA is a single stranded copy of one DNA strand.
• An enzyme called RNA polymerase attaches to a
strand of DNA and copies it.
• The copied strand is referred to as mRNA (messenger
RNA) and is the instructions on how to make proteins.
• RNA is single stranded and replaces Thymine (T) with a
new base called Uracil (U).
STEP 2: TRANSLATION
AKA: PROTEIN SYNTHESIS
• Step 1:
• The mRNA enters the ribosome (like a lace through
a shoe).
PROBLEM?
• Problem:
• There are 20 different amino acids.
• There are 4 RNA bases.
A
T
phe
C
G
ile
leu
val
met
pro
ser
ala
thr
his
tyr
asn
gln
asp
lys
cys
glu
arg
trp
gly
WHAT CODON’S REFER TO
STEP TWO: TRANSLATION
2.
Since each 3-letter combination “codes” for
an amino acid, you need to figure out what
amino acid matches up with each codon:
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA
met
?
STEP TWO: TRANSLATION
2.
Since each 3-letter combination “codes” for
an amino acid, you need to figure out what
amino acid matches up with each codon:
AUG|CGU|ACU|GAU|CGU|UCA|GAU|UGA
met
arg
thr
asp
arg
ser
asp
???
STEP 2 IN PROTEIN SYNTHESIS
• Another RNA molecule called tRNA (transfer), bind
themselves to a specific amino acid and bring them
to the ribosome.
• Humans use 20 main amino acids, there is a unique
tRNA for each amino acids.
• Recall: Proteins are made of amino acids.
STEP 2 IN ACTION
STEP 3: READING THE MRNA
• When both the tRNA and mRNA find their way into the
ribosome they check one other. Meaning:
• mRNA and tRNA have their bases read in 3’s, a
sequence of 3 bases in a row is called a “Codon.”
• If the tRNA’s “Anti-codon,” and mRNA’s “codon” are
able to base pair together, the tRNA transfers it’s amino
acid to a pocket of the ribosome.
• These amino acids are then combined with other amino
acids to create a protein.
STEP 3 IN ACTION
STEP 4: FINISH HIM!!!
• When the protein has all of it’s necessary amino
acid parts in the ribosome the mRNA tells the
process to stop by having a STOP CODON in it’s
sequence.
• The protein then travels to the Rough Endoplasmic
Reticulum (ER) or the Golgi Apparatus to be folded.
• Proteins must be folded to be functional.
WHAT CODON’S REFER TO
CLOSURE
• I got your back!
• Each person will have a vocabulary word taped to
their backs.
• Students will pair up and try and discover what’s on
their back by asking their partner questions.
CARTOON OF THE DAY!
CARTOON OF THE DAY
CARTOON OF THE DAY!
CARTOON OF DAY!
QUESTION OF THE DAY!
WRITE THE AMINO ACID SEQUENCE
FOR THE FOLLOWING CODON
SEQUENCE:
UGAAUGGAAACCCUCACUUAA
CARTOONS OF THE DAY!
SCIENCE CLUB AGENDA
•
•
•
•
Bonding Behavior/Nomenclature
Line diagrams/Intro to the mother carbon chain
Introduction to Alkane and cycloalkane naming.
Club officers and future endeavors/topic matter.
• Next week’s adventure: Introduction to Alkane
Reactions
NAMING BASICS
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-meth
-eth
-prop
-but
-pent
-hex
-hept
-oct
-non
-dec
Common Substituents:
-bromo, chloro
-methyl, ethyl
-benzyl,
QUESTIONS OF THE DAY!
• 1.) Are humans more or less intelligent on average as
compared to 1000 years ago? Explain why or why not.
• 2.) Write down the following DNA Sequence:
ATCAACGGCACGACGATC
• -Transcribe the following sequence. What is the Amino
Acid sequence?
• -Invert the 3rd and 4th codon
• -How has the amino acid sequence changed?