Download Protein Synthesis Role Modeling Activity

HW #3 Protein Synthesis
due Wednesday December 8th
Name ______________________________________ Hour ______
Due: ____________
Lab
Role
Data Table
____
Modeling
Questions
____
Lab
Cystic
Fibrosis
Data Table
____
Questions
____
Completion
____
Mutations
Activity
Your Points
____
5 possible
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Protein Synthesis Role Modeling Activity
Cooperative Learning Activity:
Student will learn the process of protein synthesis. To do so, each student will play a role in the
process of protein synthesis. Students will work in groups of three to model how information in
DNA is expressed as protein.
Roles:
 1 student will be mRNA (transcribing the code of DNA to bring outside of nucleus to the
ribosome)
 1 student will be tRNA and translate the codons at the ribosome
 1 student will be taking anticodon from ribosome to look for the correct amino acid (in this
case a word) and bring it back to the ribosome to complete a sentence)
Procedure:
1. The teacher will be at the “nucleus desk” which is where the DNA templates are located.
DNA templates cannot leave this area.
2. The student who is responsible for mRNA should come into the nucleus and pick up the DNA
template card number and transcribe it AT THE NUCLEUS desk, into mRNA (remember to
use uracil). This student (mRNA) will take the transcribed sequence to the ribosome
student’s desk where it will be translated by tRNA.
3. Once the mRNA brings the transcribed code to the ribosome the tRNA will translate or
WRITE OUT the tRNA anticodon sequence.
4. Then the Amino acid student will search out the correct anticodon card located around the
room (cytoplasm) and flip the card over revealing the word. S/he will write down the
word.
5. Once the Amino Acid Student has deciphered all the codes and completes the sentence, a
student in the group will tell the teacher their group sentence. If it is correct, then they
can move on to the next DNA template. HINT: After completing the sentence, read the
sentence. If it does not make sense, it is not correct, a mutation has occurred. Review the
DNA template card to see where the mutation took place.
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Write the DNA template # you are transcribing and then complete the translated
sentences in the spaces below:
DNA Template #
mRNA transcription:
tRNA:
AA Sentence:
__________________________________________________________________
DNA Template #
mRNA transcription:
tRNA:
AA Sentence:
____________________________________________________________________
DNA Template #
mRNA transcription:
tRNA:
AA Sentence:
__________________________________________________________________
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Analysis:
1. List three differences between DNA and RNA.
2. You discover a new coding strand of DNA and determine it has 18 -nucleotides, how many
amino acids will be in the polypeptide that is formed?
A. How many nucleotides will be in the mRNA?
B. How many anticodons will there be?
3. What is the function of mRNA?
4. What are the difference between messenger RNA and transfer RNA? How are they
similar?
5. What is transcription? Describe the process.
6. Define translation. Describe the process.
7. Do all of your sentences that you have made make sense?
8.
If one or more of your sentences do not make sense, can you explain what might have
happened to cause the mistake to occur? What is it called when a mistake occurs while
making a protein?
9. For each sentence that you have that does not make sense, can you locate the error?
Check the answers on the board in the front of the room. Did you have any sentences
that made sense but are not the same sentences on the board?
10. Explain how the same protein can be made even though there is an error located on the
DNA strand itself?
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Lab Genetic Testing for Cystic Fibrosis
1. Carefully transfer the DNA base sequence for each individual to the worksheet. Check
your work by comparing your worksheets with your lab partner.
2. Now translate the DNA code into amino acids, if there are two different amino acids
record them in the circle like this: A/V. Know then that two different versions of the
protein may be made.
Josina
DNA
DNA
“Ma”
“Pa”
Leah
Amino
Acid
DNA
DNA
“Ma”
“Pa”
Martin
Amino
Acid
DNA
DNA
“Ma”
“Pa”
Richard
Amino
Acid
DNA
DNA
“Ma”
“Pa”
Amino
Acid
1
T
T
T
T
T
T
T
T
2
A
A
A
A
A
A
A
A
3
C
C
C
C
C
C
C
C
4
T
T
T
T
T
T
T
T
5
C
C
C
C
C
C
C
C
6
C
C
C
C
C
C
C
C
7
T
T
T
T
T
T
T
T
8
T
T
T
T
T
T
T
T
9
T
T
T
T
T
T
T
T
1
G
G
G
G
G
G
G
G
10
T
T
T
T
T
T
T
T
1
C
C
C
C
C
T
C
T
12
T
T
T
T
T
T
G
G
13
T
T
T
T
T
T
G
G
14
C
C
C
C
T
G
T
T
15
G
G
G
G
G
G
G
G
16
G
G
G
G
G
G
G
T
17
T
T
T
T
T
T
T
T
18
G
G
G
G
G
G
C
A
2
T
T
T
T
T
T
A
A
9
2
T
T
T
T
T
T
G
G
0
2
A
A
A
A
A
A
1
2
A
A
A
A
A
A
2
G
G
G
G
G
G
3
a
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3. Examine the DNA base sequences of all four individuals and circle any differences. Do
any of the individuals have the same sequence in both the “maternal” and “paternal”
chromosome? If so, name the individual. Is this person homozygous or heterozygous?
4. Examine Richard's base sequences. What is different about his DNA? Propose a
hypothesis to explain your observations.
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5. Does a difference in DNA base sequence always mean a difference in the amino acid?
Explain your answer with an example from the data table.
6. If the difference in base sequence is drastically different, compare the sequence to
Josina's DNA. Josina is homozygous normal. Remember, CF is homozygous recessive.
Therefore, if one chromosome has a sequence exactly the same as Josina's, the
individual is heterozygous and does not have C, but does carry the CF gene. A carrier for
CF can make one half of their protein that is functional and will not have CF. Classify
each person as heterozygous, homozygous dominant or homozygous recessive.
JosinaLeah -
Richard -
Martin –
7. How does Martin’s amino acid sequence differ from Josina's? Do you think Martin has
CF? Why or why not?
8. Compare the amino acid sequence of Richard with Josina's. What is the defect in
Richard's amino acid sequence? What causes this difference?
9. If you wanted to determine if an individual has cystic fibrosis would you use a karyotype
or a DNA sequence?
10. If Josina and Richard have children what is the chance they would have a child with CF
(think Punnett Square, seven steps)?
11. If Josina and Martin marry what is the chance they would have children without CF?
Also, what is the chance they would have children who were carriers?
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MUTATIONS
The word “mutation” means different things to different people. For some, it makes
them think of scary scenes from their favorite sci-fi movie. For others, it stirs
memories of nuclear disasters at Three Mile Island in Pennsylvania or Chernobyl in the
former Soviet Union. Most people don’t realize that mutations are any change to the
DNA sequence. The genetic disorders that you have been researching are usually the
result of one or two nucleotides in DNA that have been changed, added, or removed.
Since DNA codes for protein, these DNA changes may result in the production of an
altered sequence of amino acids. This protein may have the wrong shape and may not
function correctly or at all. Finally, mutations happen all the time. Our body is actually
accustomed to these changes and you will find that it has a way to “plan” for some of
them.
1. What is a mutation?
2. Use your knowledge of transcription to transcribe the following DNA gene into a
mRNA code.
DNA –
ACATTGTACC CGTAGAAGTG CACTACATTG
mRNA - ________________________________________________
3. Use your amino acid code chart to determine which amino acids are going to be used
to build a protein based on the above mRNA sequence. Write your answer using the
single letter abbreviations for each amino acid. (HINT: Your answer will be
something that you might receive around your birthday)
Amino Acids -
____ _____ _____ _____ _____
4. Any change to DNA is considered to be a mutation. However, not all mutations are
created equal. Some may mean BIG changes for the protein that is produced, others
may mean small changes, while other changes may make absolutely no difference for
the final sequence of amino acids.
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Since DNA codes for mRNA, we are going to make this lesson on proteins simpler by
working with an mRNA sequence. The provided mRNA sequence is the same as the
one you made on the other side of this page (or it should be). Use your amino acid
code chart to show how the mRNA code could be changed to make each of the
different types of mutations. Be able to explain why your change is BIG, small, or
results in no change.
UGUAACAUGG GCAUCUUCAC GUGAUGUAAC
A. Mutate the above mRNA sequence to show how a mutation could lead to NO
CHANGE in the amino acids. Explain how your mutation works.
MUTANT mRNA sequence - ________________________________
Explanation:
B. Mutate the above mRNA sequence to show how a mutation could lead to a BIG
CHANGE in the amino acids. Explain how your mutation works.
MUTANT mRNA sequence - ________________________________
Explanation:
C. Mutate the above mRNA sequence to show how a mutation could lead to a
SMALL CHANGE (maybe, a one amino acid difference). Explain.
MUTANT mRNA sequence - ________________________________
Explanation:
5. How many nucleotides are required to code for an amino acid (one codon)?
6. How many different amino acids does our body use?
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7. Why can’t the body use one nucleotide to code for all of those amino acids?
8. How many different two letter combinations could be made if two nucleotides coded
for an amino acid (Hint: try to list them out – AA, AG, AC, AT, etc)?
9. Why can’t the body use two nucleotides to code for all of those amino acids?
10. Using codons of three nucleotides results in having many more codons than we have
amino acids. What’s the benefit of having so many different codons codes for so few
amino acids. Use your amino acid code chart and your answer to 4B to see if you can
determine an answer.
11. In what type of cell would a mutation have to occur in order for it to be passed on to
someone’s children?
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