Download Genetics 16 - Protein Synthesis Transcription Translation

Name ______________________________________________ Date _____________________ Period _______
Introduction (p. 366) – 6pts
(1)
What do genes determine? _________________________________________________________
(2)
Define PROTEIN SYNTHESIS ___________________________________________________________
(3)
(a) Define TRANSCRIPTION: ___________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
(b) Where does transcription take place? _____________________________________________
(4)
(a) Define TRANSLATION: ____________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
(b) Where does translation take place? _______________________________________________
Challenge:
How does a cell make proteins with the information from DNA?
Procedure Part A – Transcription and Translation
(1)
With your partner, spread out the 10 Transcription and Translation cards in front of you on the
table. Look closely at the cards.
What structures on the cards do you recognize (1 pt)?
What similarities between cards do you notice (1 pt)?
(2)
To make a protein, a cell must follow a certain order of steps:
1. Convert information in DNA into a messenger molecule
2. Get the messenger molecule to where the protein can be made
3. Use the code in the messenger molecule to translate it into a string of amino acids for the
protein chain
Place the cards in the order that you think shows the process above. Record the
order of the cards below and have your teacher check this step (1 pt):
____________________________________________________________________
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(3)
Transcription is the first step in protein synthesis. With your partner, view the protein synthesis
simulation which can be found at http://sepuplhs.org/high/sgi/teachers/genetics_act16_sim.html
or on your teacher’s Edline links.
(4)
Based on the information on the simulation answer the following questions (4 pts):
a) What molecule is made during transcription? _______________________________________
b) Where does transcription occur at in a cell? ________________________________________
c) What enzyme is responsible for allowing transcription in the cell?
_________________________________
If necessary, discuss with your partner any changes you need to make, and
rearrange the cards to reflect the correct order of events in transcription. Have
your teacher check this step
Which cards in your set represent the process of transcription?
_______________________________________________
(5)
Using what you observed in the animation and the information on the cards, fill in the
transcription section of the table on the next page BEFORE MOVING ON TO THE NEXT STEP.
(6)
Translation is the second stage of protein synthesis. View the next stage of the protein synthesis
simulation.
(7)
Based on the information on the simulation answer the following questions (3 pts):
a) What cell structure does translation occur in? ______________________________________
b) What do you call the three letter sequence of mRNA bases? ___________________________
c) What amino acid is attached to the “start” codon? ___________________________________
(8)
Drag and drop each anti-codon into place based on the mRNA sequence. Record the amino acid
chain you create below as you add each one (2 pts).
_______________________________________________________________________________
(9) What happened to your chain when you reached the codon UAA (1 pt)? ______________________
_________________________________________________________________________________
(10) What is the final product of translation (1 pt)? _________________________________________
_______________________________________________________________________________
(11) Look at the order in which you placed the cards in Step 4. Based on what you viewed in the
animation, which cards show the steps in translation (1 pt)?
_________________________________________________
Have your teacher check this step.
(12) Using what you observed in the animation, and the information provided on the cards, fill in the
translation section of the table on the next page.
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(13) Review your notes from Activity 12, “DNA Replication,” to fill in the first row of the table below.
Table 16.1 – Summary of Transcription and Translation
What happens
Subunits used to
make product
DNA replication
Transcription
Translation
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Where it happens
End product
Procedure Part B: Mutations
As you saw in Part A of this activity, DNA is a template that provides information for creating messenger RNA.
The information in mRNA is then converted into an amino acid sequence, which is then turned into a protein.
Occasionally during this process a mutation occurs. Mutations are changes in the sequence of nucleotides in a
strand of DNA. In this part of the activity, you will investigate the effect of DNA mutations on protein synthesis.
(14) With your group you will model the processes of transcription and translation and determine how
mutations will affect the product of these processes. The original DNA strand that we will begin with is
listed below.
5’ T A C C T A G C C A G T A T T 3’
(15) Each member of the group will play a different role in the process of transcription and translation. We will
then switch roles and complete the same processes for several different mutation possibilities. At the end
of the lab you will compare how the mutations affected the overall product of protein synthesis.
RNA Polymerase – Your job is to go into the “nucleus” at the front of the room and transcribe the DNA
on the table into RNA so that we can move the message out.
Ribosome – You will determine the correct amino acid needed by using the codon table provided and
tell the tRNA’s what to get.
tRNA – you will go and find the appropriate amino acids as determined by the ribosome
(16) Work through the steps to transcribe and translate the DNA using the amino acid table on the following
page. Fill in the data for the original strand on Table 16.2 on the next page.
(17) Switch jobs and complete transcription and translation using the mutated DNA strands. Record the final
products in the table on the next page. Continue to switch jobs and repeat until you have completed all
the possible strands.
(18) After completing the transcription and translation, examine each DNA strand and the effects of the
mutation on the protein product. Using the information provided in the selected DNA mutations table on
the next page, determine which mutation caused each DNA strand to be produced. Record that answer on
Table 16.2.
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Table 16.2 - Mutations
DNA
Strand
DNA sequence resulting from
DNA mutation indicated in table
Original
Strand
5’
TACCTAGCCAGTATT
3’
Final Amino Acid Sequence
5’
Mutation
TACTCTAGCCAGTATT
1
3’
5’
Mutation
TACTAGCCAGTATT
2
3’
5’
Mutation
TATCTAGCCAGTATT
3
3’
5’
Mutation
TACCTGCTAGCCAGTATT
4
3’
5
Type of mutation this
causes and evidence of
the mutation
Analysis
(1) Identify all the steps involved in making a protein from the message found in DNA and describe what
happens in each.
(2) Fill in the chart to determine amino acid sequence that results from the transcription and translation of the
following nucleotide sequence.
Original DNA
Nucleotide
5’
A
T
G
T
C
G
G
C
A
T
T
G
T
G
A
3’
Transcription
mRNA
Translation
Amino Acid
(3) What type of mutation in the DNA sequence would cause the most damage for the protein chain based on
your data? Explain your answer using evidence from Table 16.2.
(4) Do DNA mutations always cause an error in the protein that is produced? Why or why not? Give an
example to support your answer.
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