Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4a I can summarize the two main events of protein synthesis.
 I can describe what happens during transcription.
 I can describe what happens during translation.
 I can explain how transcription and translation work together to make a protein.
Lab Stn #1
Please do not move
the question to a
different lab station.
What is the purpose of transcription?
Where in the cell does it occur?
When in the cell cycle does it occur?
What is the purpose of transcription?
Transcription is the coping of a gene in DNA into mRNA. It is the first step in the flow of information from genes to
protein or, put in a simple way, it is the first of two steps in how the nucleus controls the cell.
Where in the cell does it occur?
Transcription is visible as a molecular “traffic jam” seen as a spot in the nucleus called the nucleolus (more than
one: nucleoli).
When in the cell cycle does it occur?
Transcription occurs during interphase of the cell cycle. This is when the cell makes proteins and enzymes to
catalyze metabolism and carry out their specialized task.
Examples include:
pancreatic cells exporting insulin to control blood sugar levels
adrenal gland cells exporting adrenalin for a “fight or flight” response
bacterial cells making regulatory proteins to be kept and used in the cell to regulate gene expression
eukaryotic cells making transcription factor proteins to regulate gene expression
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Unit 5 DNA to Protein
Lab Stn #2
LT4 Protein Synthesis
LT4a I can summarize the two main events of protein synthesis.
 I can describe what happens during transcription.
 I can describe what happens during translation.
 I can explain how transcription and translation work together to make a protein.
Please do not move
the question to a
different lab station.
Use the diagrams to help you to explain what happens during transcription.
Synthesis of RNA is usually catalyzed by an enzyme—RNA polymerase—using DNA as a template, a process
known as transcription. Initiation of transcription begins with the binding of the enzyme to a promoter sequence in
the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the
enzyme. The enzyme then progresses along the template strand in the 3’ to 5’ direction, synthesizing a
complementary RNA molecule with elongation occurring in the 5’ to 3’ direction. The DNA sequence also dictates
where termination of RNA synthesis will occur.[20]
Primary transcript RNAs are often modified by enzymes after transcription. For example, a poly(A) tail and a 5'
cap are added to eukaryotic pre-mRNA and introns are removed by the spliceosome.
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Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4a I can summarize the two main events of protein synthesis.
 I can describe what happens during transcription.
 I can describe what happens during translation.
 I can explain how transcription and translation work together to make a protein.
Lab Stn #3
Please do not move
the question to a
different lab station.
How is RNA “edited” before it leaves the nucleus?
Answer:
The RNA is capped at the 5’ end and a poly-A tail (a set of many adenine nucleotides) is added to the 3’ end.
This protects the molecule from being digested.
Non-coding segments of the RNA transcript are edited out. These segments are called introns. The parts that
are kept to make protein are called exons. “Exons are expressed!” The protein complex that performs this
editing is called a spliceosome.
Mrs. Loyd 
cschmittloyd@waukeeschools.org
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Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4a I can summarize the two main events of protein synthesis.
 I can describe what happens during transcription.
 I can describe what happens during translation.
 I can explain how transcription and translation work together to make a protein.
Lab Stn #4
Please do not move
the question to a
different lab station.
What is the purpose of translation?
Where in the cell does it occur?
When in the cell cycle does it occur?
What is the purpose of translation?
Translation uses the triplet code contained in mRNA to synthesize a sequence of amino acids into a polypeptide.
It is the second step in the flow of information from genes to protein or, put in a simple way, it is the second of two
steps in how the nucleus controls the cell.
Where in the cell does it occur?
Translation occurs in the cytoplasm. It begins when the mRNA is locked between the subunits of a ribosome.
If the protein is to be used in the cell, the ribosome remains “free” in the cytoplasm (attached to cytoskeleton) and
the polypeptide is made there and released into the cytoplasm.
If the protein is for export, the ribosome/mRNA complex moves to the rough endoplasmic reticulum (rER) where it
attaches to a port. The resulting polypeptide threads into the interior (lumen) of the rER where it is processed. It
then moves through the endomembrane system via transport vesicles to the Golgi bodies and from there to the
plasma membrane where it is exported across the plasma membrane using exocytosis.
When in the cell cycle does it occur?
Translation occurs during interphase of the cell cycle. This is when the cell makes proteins and enzymes to
catalyze metabolism and carry out their specialized task.
Mrs. Loyd 
cschmittloyd@waukeeschools.org
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Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4a I can summarize the two main events of protein synthesis.
 I can describe what happens during transcription.
 I can describe what happens during translation.
 I can explain how transcription and translation work together to make a protein.

Lab Stn #5
Please do not move
the question to a
different lab station.
Use the diagram to help you to explain what happens during translation.
Answer:
Translation is the process in which cellular ribosomes synthesize proteins.
In translation, messenger RNA (mRNA)—produced by transcription from DNA—is decoded by a ribosome to
produce a specific amino acid chain, or polypeptide. The polypeptide later folds into an active protein and
performs its functions in the cell.
The ribosome facilitates decoding by causing the binding of complementary tRNA anticodon sequences to
mRNA codons. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA
passes through and is "read" by the ribosome. The entire process is a part of gene expression.
In brief, translation proceeds in four phases:
1. Initiation: The ribosome assembles around the target mRNA. The first tRNA is attached at the start codon.
2. Elongation: The tRNA transfers an amino acid to the tRNA corresponding to the next codon.
3. Translocation: The ribosome then moves (translocates) to the next mRNA codon to continue the process,
creating an amino acid chain.
4. Termination: When a stop codon is reached, the ribosome releases the polypeptide.
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Lab Stn #6
Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4a I can summarize the two main events of protein synthesis.
 I can describe what happens during transcription.
 I can describe what happens during translation.
 I can explain how transcription and translation work together to make a protein.
Please do not move
the question to a
different lab station.
Use the diagrams to explain how transcription and translation work together to make a protein.
Answer:
In transcription, DNA bases are paired with complementary RNA bases according to the base-pairing rules: C-G
and A-U. The enzyme RNA polymerase catalyzes this reaction using ATP. The number of DNA base-pairs is
determined by the number of amino acids in the resulting polypeptide. The length of DNA corresponds to a gene.
The pairing is only temporary and the RNA peels away and the DNA strands reunite using hydrogen bonds. This
is seen at the nucleolus in the cell’s nucleus.
To protect the molecule from digestion, a 5’ cap and a poly-A tail are added to the ends.
The resulting mRNA transcript undergoes processing to remove noncoding segments called introns and then
joins the coding portions, called exons, into one continuous molecule. The molecule can now leave the nucleus
through a nuclear pore and enter the cytoplasm.
The mRNA transcript is joined by a free ribosome which has two spaces for tRNA’s carrying their amino acids.
The tRNA’s have nitrogen bases called an anticodon which is complementary to the mRNA’s codon. Three bases
are required to code for all 20 amino acids. The ribosome “reads” each codon matching it to the correct tRNA
and, doing so, creates the polypeptide chain which becomes a protein.
Mrs. Loyd 
cschmittloyd@waukeeschools.org
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Lab Stn #7
Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4b. I can identify how each type of RNA is involved in protein synthesis.
Where do rRNA and tRNA come from?
Please do not move
the question to a
different lab station.
All types of RNA are coded for by their own genes in the DNA.
Talk through the process using the notes in the diagram.
Mrs. Loyd 
cschmittloyd@waukeeschools.org
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Lab Stn #8
Unit 5 DNA to Protein
LT4 Protein Synthesis
Please do not move
the question to a
different lab station.
LT4c. I can describe the functions of proteins with examples.
From your macromolecule study sheet, list the functions of proteins, including membrane
proteins, and give specific examples.
Macro-molecule
Building
Blocks (monomers)
Examples
Functions
Notes
Functions
Notes
sucrase
enzymatic
bond: peptide bond between
carboxyl and amino group of 2 amino
acids.
transmembrane
transport, relay
insulin
messengers
antibodies
immunity
muscles, hair,
skin, fingernails
structural
Proteins
Macromolecule
Proteins
Building
Blocks
(monomers)
amino
acids
Mrs. Loyd 
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Examples
Page 8 of 21
Primary level of folding: sequence of
AA
Higher levels of folding determine
the polypeptide’s shape.
Normal shape = normal function
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Lab Stn #9
Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4d. I can explain how organelles function in protein synthesis.
From your cell functions study sheet and the diagram, explain how organelles function in protein
synthesis of a protein to be kept by the cell and one for export.
Fill in the table for the specific contribution that the organelle makes to protein synthesis.
Please do not move
the question to a
different lab station.
Nucleus:
Nuclear Envelope:
Nuclear Pores:
Nucleolus:
Mitochondria:
Ribosomes:
Rough Endoplasmic Reticulum
Transport vesicles
Golgi Apparatus
This is known as the endomembrane system.
Nuclear Envelope:
Controls the activity of the cell by using the genes in DNA to code for protein. DNA is the
heritable material.
Separates the nucleus and its contents (DNA) from the rest of the cell.
Nuclear Pores:
allow passage of molecules in and out of the nucleus.
Nucleolus:
site of RNA synthesis off of DNA.
Mitochondria:
break down glucose to make ATP needed for the anabolic process of building molecules.
Nucleus:
Ribosomes:
Rough Endoplasmic
Reticulum
Transport vesicles
Golgi Apparatus
organize production of protein, free ones make protein to be kept by cell, attached ones make
protein for export
Processes phospholipids and proteins for export
Carry proteins from the rER to the Golgi and from there, to the plasma membrane for export.
Modifies proteins, adds “address labels,” packages protein for export.
Mrs. Loyd 
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Lab Stn #10
Unit 5 DNA to Protein
LT4 Protein Synthesis
LT4d. I can explain how organelles function in protein synthesis.
CHALLENGE: Can prokaryotic cells make protein using transcription and translation like
eukaryotic cells do? Look through the functions of the parts for prokaryotic cells and use this as
evidence for your answer.
Please do not move
the question to a
different lab station.
Prokaryotic Parts and Functions: (*Unique to prokaryotic cells. Parts that are common to eukaryotic cells have a simpler,
prokaryotic composition.)
1. *Capsule: sticky coating on outside of some prokaryotes that helps non-motile bacteria stick, may hide cell from host’s
immune system.
2. Cell Wall: rigid, provide structure, protection, back-pressure for turgidity.
3. Cytoskeleton: used like tent poles to support structure, used as internal tracks on which items move or anchor
4. Flagella: (sg: flagellum) long and few in #, propulsion (prokaryotes do not have cilia)
5. *Nucleoid Region: area containing DNA that is used to control the cell and is the hereditary material.
6. *Pili: (sg: Pilus) Short projections on the surface of a prokaryotic cell that helps the cell attach to other surfaces. Specialized
sex pili are used in conjugation (sharing DNA) to hold the cells together.
7. Plasma Membrane: Controls what enters and leaves the cell.
8. Ribosomes: organize production of protein.
Answer:
Yes, prokaryotic cells use transcription and translation to make protein. In order to do this, these cells would need to have
DNA, RNA and ribosomes, which they have. Translation would be different in one important aspect. Without a nuclear
envelope to separate transcription from translation, BOTH processes occur simultaneously.
Mrs. Loyd 
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Lab Stn #10
Unit 5 DNA to Protein
PAGE 1
LT4: Vocabulary: transcription, translation, RNA, mRNA, rRNA, tRNA, protein, amino acid, codon,
anticodon, ribose, uracil, ribosome, introns, exons
Use the flashcards to practice the vocabulary for this learning target.
Cut these out and fold to make flashcards.
Please do not move
the question to a
different lab station.
DNA is used as a template to make mRNA to carry the
code into the cytoplasm to make protein.
Transcription
Converting the nitrogen base code (mRNA)
into amino acids (protein). Transfer RNA
(tRNA) is the link (“translator”) between the
two “languages.”
Translation
RNA
Ribonucleic Acid:
ribose sugar, nitrogen base, phosphate group.
3 forms: mRNA, rRNA, tRNA
Uses Uracil instead of Thymine
Single stranded
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RNA made using DNA as a template at the
nucleolus. Carries the code for protein from
the nucleus into the
cytoplasm to make
protein.
mRNA
RNA made using DNA as a template at the
nucleolus. rRNA combines with protein to
make up the ribosome. Two subunits: small
and large. Ribosomes organize protein
synthesis in the cytoplasm.
rRNA
tRNA
Mrs. Loyd 
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A type of RNA that carries a specific amino acid on one
end and an anticodon to match up with the mRNA
codon on the other end. The “t” stands for “transfer”
but it is
useful to
remember
that it
“translates”
and works
like a “taxi.”
The images
show the 2D and 3-D
shapes.
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Lab Stn #11
Unit 5 DNA to Protein
PAGE 2
LT4: Vocabulary: transcription, translation, RNA, mRNA, rRNA, tRNA, protein, amino acid, codon,
anticodon, ribose, uracil, ribosome, introns, exons
Protein
Please do not move
the question to a
different lab station.
A sequence of amino acids that folds on
itself and creates a unique 3-D shape that
determines its functions.
The building block of protein (polypeptides). 20
different A.A.’s in protein. Differ by their side
chains (R).
Amino
Acid
Codon
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The sequence of three nitrogen bases in
mRNA that codes for a specific amino
acid.
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Anticodon
The sequence of three nitrogen bases in
tRNA that are complementary to the
mRNA codon for an amino acid.
Ribose
A pentose sugar with an –OH group at the
#2 carbon. The sugar in RNA.
Uracil
The nitrogen base unique to RNA.
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Lab Stn #12
Unit 5 DNA to Protein
PAGE 3
LT4: Vocabulary: transcription, translation, RNA, mRNA, rRNA, tRNA, protein, amino acid, codon,
anticodon, ribose, uracil, ribosome, introns, exons
Please do not move
the question to a
different lab station.
Ribosomes
Organelle that organizes protein synthesis in
the cytoplasm of ALL cells.
Is not membrane-bound.
Introns
Noncoding nucleotide sequences that occur
between exons (coding DNA) and is
removed during post-transcriptional
modification. Bacteria do not have introns.
Exons
Sequences of mRNA that code for amino
acids.
“Exons are expressed.”
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Translation
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Ribosomes organize
protein synthesis using
the mRNA nitrogen
base triplet code to put
tRNA amino acids in
order. The ribosome
then creates a peptide
bond between the
amino acids to create a
polypeptide or protein.
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Lab Stn #1
Unit 5 DNA to Protein
LT5. Mutations
Please do not move
the question to a
different lab station.
LT5a I can define what a mutation is and how it affects proteins.
Define mutation.
Translate the mRNA into amino acids and analyze the result.
Explain how the following mutations affect the amino acid sequence of the polypeptide (protein).
Type of
Mutation
Substitution of
one DNA base
for another
Normal mRNA and A.A.’s
AUG-UAC-UUU-GGC-GAA
Met - Tyr - Phe - Gly - Glu
AUG-UAC-UUU-GGA-GAA
AUG-UAC-UUU-AGC-GAA
AUG-UAG-UUU-GGC-GAA
Insertions or
deletions of
DNA nucleotides cause a
frame-shift
mutation.
AUG-UAC-UU_ -GGC-GAA
Effect
Silent mutations result in ____________
_______ due to the wobble effect.
Missense mutation results in ________
________________________________.
This may or may not change the shape
and function of the protein.
Nonsense mutations change an amino
acid codon to_____________________.
Frame-shift mutations can shift the
reading frame resulting in
Use either code diagram. The round one starts in the middle and works outward.
Answers on the back.
Lab Stn #1
ANSWER:
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different lab station.
Definition: Mutations are changes in the DNA base sequence, caused by errors in DNA replication or recombination (like
crossing over) or by mutagens (like radiation or toxic chemicals). Substituting, deleting, or inserting nucleotides in a gene
has varying effects on the polypeptide and organism.
Translate the mRNA into amino acids and analyze the result.
Explain how the following mutations affect the amino acid sequence of the polypeptide (protein).
Type of
Mutation
Substitution of
one DNA base
for another
Examples
Normal mRNA and A.A.’s
AUG-UAC-UUU-GGC-GAA
Met - Tyr - Phe - Gly - Glu
AUG-UAC-UUU-GGA-GAA
AUG-UAC-UUU-AGC-GAA
AUG-UAG-UUU-GGC-GAA
Insertions or
deletions of
DNA
nucleotides
cause a frameshift mutation.
AUG-UAC-UU_ -GGC-GAA
Mrs. Loyd 
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Effect
Silent mutations result in no change to
amino acids due to the wobble effect.
Missense mutation results in a trade of
one amino acid for a different one. This
may or may not change the shape and
function of the protein.
Nonsense mutations change an amino
acid codon to a stop codon.
Frame-shift mutations can shift the
reading frame resulting in altered triplet
groups and greatly change the amino
acid sequence or put in a very premature
stop codon. This would, most likely,
render the protein useless.
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Lab Stn #2
Unit 5 DNA to Protein
LT5. Mutations
Please do not move
the question to a
different lab station.
LT5b I can identify factors that lead to mutations.
Describe two factors that can lead to mutations.
Answer:
Mutations happen for several reasons.
DNA fails to copy accurately
Most of the mutations that we think matter to evolution are
"naturally-occurring." For example, when a cell divides, it
makes a copy of its DNA — and sometimes the copy is not
quite perfect. That small difference from the original DNA
sequence is a mutation.
External influences can create mutations
Mutations can also be caused by exposure to specific chemicals (toxins) or radiation. These
agents cause the DNA to break down. This is not necessarily unnatural — even in the most
isolated and pristine environments, DNA breaks down. Nevertheless, when the cell repairs the
DNA, it might not do a perfect job of the repair. So the cell would end up with DNA slightly
different than the original DNA and hence, a mutation.
Mrs. Loyd 
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Unit 5 DNA to Protein
Lab Stn #3
LT6. Summary
LT6 I can explain the relationship between genes and traits.
Please do not move
the question to a
different lab station.
Answer:
DNA is our genetic code. It is not our traits but codes for the amino acids that make up our proteins that give us
our traits. Genetic diseases may be due to faulty enzymes, non-functional receptor proteins on the surface of
cells, the lack of functional hydrolytic enzymes in lysosomes, or the lack of messenger molecules like insulin to
name just a few. Melanin is a protein that causes our skin, hair and eyes to create our coloration. Proteins have
so many different functions that a mutation will likely affect the organism.
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Unit 5 DNA to Protein
LT6
Use the diagram to help you to explain how transcription and translation work
together to make protein.
Lab Stn #4
Please do not move
the question to a
different lab station.
Answer:
In transcription, DNA bases are paired with complementary RNA bases according to the base-pairing rules: C-G
and A-U. The enzyme RNA polymerase catalyzes this reaction using ATP. The number of DNA base-pairs is
determined by the number of amino acids in the resulting polypeptide. The length of DNA corresponds to a gene.
The pairing is only temporary and the RNA peels away and the DNA strands reunite using hydrogen bonds. This
is seen at the nucleolus in the cell’s nucleus.
To protect the molecule from digestion, a 5’ cap and a poly-A tail are added to the ends.
The resulting mRNA transcript undergoes processing to remove noncoding segments called introns and then
joins the coding portions, called exons, into one continuous molecule. The molecule can now leave the nucleus
through a nuclear pore and enter the cytoplasm.
The mRNA transcript is joined by a free ribosome which has two spaces for tRNA’s carrying their amino acids.
The tRNA’s have nitrogen bases called an anticodon which is complementary to the mRNA’s codon. Three bases
are required to code for all 20 amino acids. The ribosome “reads” each codon matching it to the correct tRNA
and, doing so, creates the polypeptide chain which becomes a protein.
Mrs. Loyd 
cschmittloyd@waukeeschools.org
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