Before You Begin, Save This Lab Report Template on Your Computer As Lastnameapbiotrans

Name ______

Translation Lab

Before you begin, save this Lab Report Template on your computer as LastNameAPBIOTrans

Go to Biology Labs Online site (http://www.biologylabsonline.com) and log onto the Translation Lab

Read all the instructions below BEFORE you start! It will help if you print out this template to use as you perform the lab.

Read the Background Information on transcription, translation, the wobble hypothesis, DNA, RNA, nucleotides, and point mutations so that you understand the terms used in this online lab.

To start the Translation Lab, click the START LAB link just under the Welcome to Translation Lab title or scroll down on the left if you are in the Assignments window. Wait for the Translation Lab to open. You will see The Translation Laboratory. Click on each item to identify it and determine what it does. You should see flasks containing RNA nucleotides, an RNA synthesizer, a DNA synthesizer, and a test-tube for the Translation Mix. Once you have identified the equipment, click Start Experiment to enter the lab itself.

Practice:

1. Click on each bottle and select a nucleotide from each. For this practice, it does NOT matter which nucleotides you select.

2. Click Make RNA. You will see a sequence of nucleotides corresponding to the letters you selected.

3. Click add to notes: This sequence will now appear in page one of the notebook.

4. Click To Translation Mix: The nucleotides will be mixed, placed in the protein synthesizer, and a polypeptide sequence will be produced.

5. Click add to notes: This sequence will now appear in page one of the notebook.

6. Copy and paste these sequences in the Practice Chart in the Results Section below.

7. Click New Experiment. This will return you to the RNA mixing area.

8. Repeat the procedures several times with different sequences of nucleotides until you are comfortable with the process. Copy and paste the results of your mixes in the Practice Chart below in the Results section

Assignment 1: The Genetic Code and Protein Synthesis (modified from online Assignment 1)

Use the basic directions above to synthesize amino acid sequences from the RNA sequences indicated below. After you have added the sequences to the notes, copy and paste them in Data Chart 2 or Data Chart 3 below in the Results section.

Single Nucleotide and Dinucleotide Sequences

1. Poly U (select a U from each RNA flask)

2. Poly A (select an A from each RNA flask)

3. Poly G

4. Poly C

5. UA… (select U from flask 1, A from flask 2, nothing from the other 2 flasks)

6. AU… (select A from flask 1, U from flask 2, nothing from the other 2 flasks)

7. AC…

8. CA…

9. AG…

10. GA…

11. UC…

12. CU…

13. UG…

14. GU…

15. GC…

16. CG…

Trinucleotide and Tetranucleotide Sequences using A and C (Record the RNA and amino acid sequences in Data Chart 3)

1. AAC… (select A from flask 1, A from flask 2, C from flask 3, and nothing from flask 4)Note that you get 3 different amino acid chains, depending on where translation started! Add to notes and copy and paste ALL THREE amino acid sequences into Data Chart 3

2. CAA… (select C from flask 1, A from flask 2, A from flask 3, and nothing from flask 4)

3. ACA… (select A from flask 1, c from flask 2, A from flask 3, and nothing from flask 4)

4. CACUse these results, the process of elimination, and the results from the dinucleotide trials above to determine what amino acid is coded for by ACA. and ACC

Now try the next series:

5. CAAG… (this is a tetranucleotide)

6. AACG… Note, you will only get one amino acid sequence from the tetranucleotides. Use these results, the process of elimination, and the results from the dinucleotide trials above to determine what amino acid is coded for by CAA.

7. On your own and using your results so far, try to assign amino acids to all other possible combinations of C and A. Indicate in Data Chart 3 your trail sequences and your codon assignments. You can use U and G in the elimination trials!

Trinucleotideand Tetranucleotide Sequences using A and U (Record the RNA and amino acid sequences in Data Chart 3)

1. AU … You can copy this from Data Chart 1 if you want

2. AAU

3. AUU

4. List any codon assignments you were able to make from these trials. Use tetranucleotides to figure out which amino acids go with codons that can be produced using only A and U.

Trinucleotideand Tetranucleotide Sequences using G (Record the RNA and amino acid sequences in Data Chart 3)

Use the same processes as above to determine the amino acids coded by

1. GGG

2. GGA

3. GGC

4. GGU

Assignment 2: Mapping Other Mutations (corresponds to Online Assignment 2)

The purpose of this assignment, which is much shorter than the previous one, is to demonstrate the effect of a point mutation on the amino acid sequence of a protein. For this demonstration, you need to know that sickle-cell disease is a genetic disease that results from a point mutation in the 2nd nucleotide of the codon GAA, resulting in a change in the amino acid at position 6 in the hemoglobin protein. You will study this protein and the effects of other point mutations on hemoglobin activity in the Hemoglobin Lab.

1. Clear the notebook page.

2. Click New Experiment

3. Synthesize RNA and amino acid sequences from the following codons:

a. GAA

b. GUA

c. GAG

4. Copy and paste the RNA and amino acid sequences into Data Chart 4 below in the results section.

5. Assign codons to each amino acid produced by these sequences, performing any other RNA/amino acid synthesis trials necessary to confirm your codon assignments.(HINT: Remember that UAA, UAG, and UGA are STOP codons and that AUG is a START codon)

Results:

Data Chart 1: Practice RNA and Amino Acid Sequences

Trial

RNA Sequence

Amino Acid Sequence

/ /

Data Chart 2: Single Nucleotide and Dinucleotide Sequences

Trial

RNA Sequence

Amino Acid Sequence

poly U

/ /

poly A

/ /

poly G

/ /

poly C

/ /

Data Chart 3: Trinucleotide and Tetranucleotide Sequences with A and C

Trial

RNA Sequence

Amino Acid Sequence

AAC

/ /

CAA

/ /

ACA

/ /

CAC

/ /

ACA codes for ______ACC codes for ______

CAAG

/ /

AACG

/ /

CAA codes for ______

Data Chart 4: Point Mutation in GAA

Trial

RNA Sequence

Amino Acid Sequence

GAA

/ /

GUA

/ /

GAG

/ /

GAA codes for ______GUA codes for ______GAG codes for ______

Discussion and Analysis:

1. Compare/contrast the various RNA and amino acid sequences produced by dinucleotide and trinucleotide sequences, using the following prompts:

a. Did you get the same or different results from UA and AU, UG and GU, UC and CU, CG and GC?

b. Which amino acids were included in polypeptide chains coded using 2 letter RNA sequences?

c. Which amino acids were missing in polypeptide chains coded using 2 letter RNA sequences?

2. Discuss the process of determining codon sequences.

3. What unusual results did you get from your trials with the A- and U-containing tri- and tetranucleotides. Explain these results, referring to your understanding of the genetic code.

4. How do the results from your various RNA mixing trials relate to the Wobble hypothesis? (Define the Wobble hypotheses as part of your answer)

5. Which amino acid is incorporated into the sickle-cell hemoglobin molecule when this codon is mutated to GUA?

Conclusion:

NOT Required.
You should have indicated your codon assignments in the data charts above in the results section.

Reflection: Comment on what you learned by doing this lab.

AP Biology Johns Hopkins Center for Talented Youth 2006/2007