Download Notes Protein Synthesis 2016

Protein Synthesis
Notes: The Big Picture
• All cells in an organism contain an
entire copy
__________________
of that organism’s
genetic code.
• Restate:
• How do all the cells of an organisms contain
the same DNA? (Hint: What process?)
Mitosis
Where do all of the cells in your
body come from?
Questions
Do all of the cells in your body have the same:
• Structure?
• Function?
Neuron
• Deoxyribonucleic Acid?
Epithelial Cells (Skin)
Example:
• The Pancreas contains a complete copy of
your DNA, but the gene for insulin (among
others) is activated (on).
• Would the adrenal gland have an entire copy
of your DNA?
• Would your adrenal gland have the gene for
insulin activated (on)?
Notes: The Big Picture
• How do specialized cells know which part of
the genetic code they are responsible for?
• Specialized cells have different genes
expressed (turned on). Those genes allow
specific proteins to be synthesized, which
aides their function.
• This process is CALLED:
Cell
Differentiation
HOW do genes become activated?
Any ideas?
What conclusion can you make
based on the data below?
Warmer T = More Males
Colder T = More Females
Conclusion:
Male
Female
Huh?
• How did this happen?
• What did the temperature “do” to the baby
turtles?
• Increased temperatures activate the genes
that allow the turtles to become males.
True for Ridley Sea
Turtle…but NOT
Humans
Notes: The Big Picture
• How can genes be activated?
• Environmental Factors
– Temperature
– Smoking/pollutants
– Light
• Chemicals
– Oxygen
– Drugs
Summary• Use the terms cell differentiation, genetic
code, and expressed to summarize today’s
lesson.
• Cell differentiation allows the genetic code to
have certain parts expressed.
Protein Synthesis Unit
Learning Targets
• The point is to understand how cells use DNA
to create traits.
• By the end of this unit you will describe how
DNA codes for traits, the steps of protein
synthesis, & how environmental and chemical
factors affect gene expression in organisms.
DNA Characteristics
• Basic Central Dogma:
Proteins  ________
________
________
DNA
Traits
Double helix
Chromatin (in the
Chromosome
nucleus)
• Sugar (Deoxyribose)
• Phosphate
• Nitrogen base
• Nitrogen Base
+ sugar
+ Phosphate =
A NUCLEOTIDE
• The order of the nitrogen bases tell your cells
to make certain proteins.
• DNA codes for PROTEINS.
• DNA
Proteins
DNA
Transcription
Nucleus
mRNA
Ribosome
Translation
Protein
Traits
• Added mRNA
DNA
mRNA
Will this be true for all kingdoms?
Yes, except for
bacteria.
Protein Synthesis
Compare/ Contrast DNA & mRNA.
mRNA vs. DNA
mRNA is very similar to DNA….but there are
differences.
How many strands does DNA have?
2 strands, DNA is double stranded.
mRNA has only 1 strand.
mRNA is single stranded.
mRNA vs. DNA
What kind of sugar is found in DNA?
Deoxyribose is the sugar in DNA.
mRNA has a different sugar.
Ribose is the sugar in RNA
mRNA vs. DNA
What are the 4 nitorgen bases in DNA?
A- Adenine
G- Guanine
C- Cytosine
T- Thymine
What do each pair up with?
A—T G—C
mRNA vs. DNA
mRNA does not have a “T” (Thymine) and
instead has a “U” for Uracil. Therefore, what
are the four nitrogen bases for RNA?
DNA
RNA
U
A
T
G
C
U
A
C
G
T
mRNA vs. DNA
What is DNA’s job/function?
It is your genetic information that codes
for mRNA.
mRNA’s job is to code for specific proteins. What
do the proteins eventually make?
Traits
mRNA vs. DNA
Where is DNA always
located?
Nucleus.
Can DNA ever leave the nucleus?
No, its too large.
Nucleus , it
Because DNA cannot ever leave the _________
must code for another form to leave the nucleus.
Compare DNA & RNA
• Similarities:
They both have
nucleotides.
Compare DNA & RNA
Differences:
DNA
DNA
RNA
RNA
Strands:
Double
Single
Sugar:
Deoxyribose
Ribose
Nucleotides:
DNADNA
AT
DNA RNA
AU
CG
C G
TA
TA
GC
G C
Job:
codes for mRNA
codes for proteins
Location:
nucleus
nucleus & cytoplasm - ribosomes
Explore
You just ate ice cream
and drank a Dr.
Pepper. Your body
must secrete Insulin
(a protein).
Where are the instructions?
Where are proteins made?
What are the specifics?
DNA
Transcription
Nucleus
mRNA
Ribosome
Translation
Protein
Traits
Transcription
Transcription=
The process of making mRNA from DNA.
Is transcription happening in every gene every
second? Yes
If DNA cannot leave the nucleus, then where must
transcription occur?
In the nucleus.
***mRNA is the blueprint for converting the
message of DNA into proteins.
Process of Transcription
• Transcription Animation
Draw Transcription
Elaborate:
•
•
•
•
Have we made a protein yet?
What if this was a fungi?
Bacteria?
Plant?
Elaborate
• Predict what
would happen if
the gene for insulin
was added to a
bacterial cell.
Skip Page 10
• We will come back to this page tomorrow
Complete Venn Diagram
DNA vs. RNA
•Double strand
•Thymine
•Adenine
•Nucleus
•Guanine
•Strores genetic
•Cytosine
info
•Comprised
•Double helix
of
shape
Nucleotides
•Goes through
Replication
•Deoxyribose sugar
•Single strand
•Uracil
•Cytoplasm
•Made of 3 base
units = codons
•Ribose sugar
Translation
Each codon codes for a specific amino acid. A
codon chart is used to easily determine the
amino acid that each codon codes for.
Practice: Which amino acid do each of these
codons code for?
UUA
CCC
AGA
GAC
Determine which amino acid UUA codes for?
Translation
Each codon codes for a specific amino acid. A
codon chart is used to easily determine the
amino acid that each codon codes for.
Practice: Which amino acid do each of these
codons code for?
UUA
CCC
AGA
GAC
Leucine
Determine which amino acid CCC codes for?
Translation
Each codon codes for a specific amino acid. A
codon chart is used to easily determine the
amino acid that each codon codes for.
Practice: Which amino acid do each of these
codons code for?
UUA
CCC
AGA
GAC
Leucine
Proline
Determine which amino acid AGA codes for?
Translation
Each codon codes for a specific amino acid. A
codon chart is used to easily determine the
amino acid that each codon codes for.
Practice: Which amino acid do each of these
codons code for?
UUA
CCC
AGA
GAC
Leucine
Proline
Arginine
Determine which amino acid GAC codes for?
Translation
Each codon codes for a specific amino acid. A
codon chart is used to easily determine the
amino acid that each codon codes for.
Practice: Which amino acid do each of these
codons code for?
UUA
CCC
AGA
GAC
Leucine
Proline
Arginine
Aspartic
Acid
Translation
Notice: multiple codons code for the same
amino acid.
Practice: Which two codons code for histidine?
CAU & CAC
Ribosome
RNA
Translation
Nucleus
DNA
Transcription
Central Dogma?
Protein
DNA
Transcription
Nucleus
mRNA
Ribosome
Translation
Protein
Traits
Translation
Translation
Translation Animation
Translation=
The process where mRNA codes for
proteins using tRNA.
Is translation occuring
In every gene every
second?
Yes, when proteins
are needed
Translation
How mRNA codes for proteins using tRNA.
Amino acid
tRNA
Anti codon
mRNA
Codon
Translation
Key players in Translation:
Codon: 3 mRNA bases.
Anticodon: 3 tRNA bases that match the
mRNA sequence.
Protein: A chain of amino acids made in the
ribosome ( in the cytoplasm).
aa
aa
Protein
aa
aa
Translation
Amino Acid: Attached to the end of tRNA,
monomer of a protein
tRNA: Translation uses another
RNA called tRNA.
Shape
Like a cloverleaf or t
Draw Translation.
Elaborate:
•
•
•
•
Have we made a protein yet?
What if this was a fungi?
Bacteria?
Plant?
Elaborate
• Could a plant do
the same thing
with the gene for
insulin?
Protein Synthesis
Central Dogma?
DNA
Transcription
Nucleus
mRNA
Ribosome
Translation
Protein
Traits
Can any step in the process of protein synthesis
be regulated? Yes
What is the result if any step in the process does
not occur correctly? The protein might be incorrect
which will affect the trait.
Mutation
What is a mutation?
A change in DNA.
NOVA Video: ONE WRONG LETTER, Watch part 3.
Mutation during replication:
What happens during replication?
DNA copies itself. Sometimes DNA copies itself
incorrectly; then mRNA is made & it is
incorrect.
Mutations
There are 3 types of mutations:
1. Substitution:
Question: If a codon ACA changes to
AUA will the codon change?
Yes.
Question: If a codon ACA changes to
Yes.
AUA will the amino acid change?
Mutations
1. Substitution: (Continued)
Question: If a codon ACA changes to
NO.
ACU will the amino acid change?
Question: If a codon ACA changes to
ACU what will happen to the proteins?
Nothing will happen to the
protein because the codons
code for the same amino acid.
Mutations
1. Substitution: (Continued)
Will a change in mRNA change the
Yes.
codon?
Will a change in mRNA always change
the amino acid?
NO, not always.
Will a change in amino acid change the
protein?
Yes.
Mutations
2. Insertion:
Example:
A THE CAT ATE THE RAT
Does the sentence now mean the same thing?
NO.
Which codons changed?
All codons to the right of the insertion change.
Mutations
3. Deletion:
Example:
AUG
MET
ACA
THR
GGU
GLY
UGU
CYS
UGA
STOP
GUU
GA
Order:
AUG AAG
aa’s:
MET
LYS
GUU
VAL
VAL
Mutations
Original DNA:
mRNA:
aa’s:
Example:
GATTACA
Mutated DNA:
GGTTACA
C U A AUG U
CCAAUGU
LEU
PRO
MET
MET
Did the protein change?
Yes.