PROTEIN SYNTHESIS WORKSHEET
PART A. DNA History
Griffith and Transformation
1. What did Frederick Griffith want to learn about bacteria?
2. Circle the letter of each sentence that is true about Griffith’s experiment.
a. Mice injected with bacteria from smooth colonies died.
b. Mice injected with bacteria from rough colonies died.
c. Mice injected with heat-killed bacteria from smooth colonies died.
d. Mice injected with a mixture of bacteria from heat-killed smooth colonies and live rough colonies died.
3. Which of the 4 results from Griffith’s experiment suggested that the cause of pneumonia was not a chemical
poison released by the disease-causing bacteria?
4. What is transformation?
Avery and DNA
5. Briefly describe how Avery and his group determined which molecule (protein, RNA, DNA) was most
important for transformation.
6. Transformation did not occur when
was destroyed.
7. What was the main conclusion from Avery’s experiments?
The Hershey-Chase Experiment
8. What is a bacteriophage?
9. Circle the letter of the molecule for which radioactive phosphorus (32 P) is used as a radioactive
marker.
a. protein
b. lipid
c. DNA
d. carbohydrate
10. What results did Hershey and Chase observe (what happened when bacteria were infected with
radioactive phosphorous? Radioactive sulfur?)
11. Hershey and Chase concluded that the genetic material of the bacteriophage was
.
Components and Structure of DNA
12. According to Chargaff’s rules, the percentages of
are equal to thymine and the percentages of
are equal to guanine in the DNA molecule.
13. Rosalind Franklin’s work with X-ray diffraction showed that the DNA molecule is shaped like a(an)
and contains
strands.
14. How did Watson and Crick describe the structure of DNA?
Important Figures: Matching
Match the statement with the scientist’s experiment to which it corresponds. Answers may be used more than
once. Not all answers have to be used.
a.
Frederick Griffith
b.
Oswald Avery
c.
Alfred Hershey and Martha Chase
d.
Erwin Chargaff
e.
James Watson and Francis Crick
f.
Rosalind Franklin and Maurice Wilkins
1. _
Determined that adenine bonds to thymine and cytosine bonds to guanine
2.
Built 3-D models of the DNA molecule
3.
Took x-rays of DNA strands
4.
Proved that the cause of pneumonia was not a chemical poison released by bacteria
5.
Concluded that DNA carries genetic information
First to discover the identity of the “transforming” factor
6.
Tried to determine which parts of a virus infect the inside of bacteria
7.
8.
9.
10.______
Used others x-ray photos to determine the structure of DNA
Observed that the amount of adenine equals the amount of thymine, and that the
amount of guanine equals the amount of cytosine in any sample of DNA
Determined that the protein core of a virus is not what enters and infects bacteria
Part B: DNA and RNA Review
Read each question and fill in the proper answer.
1. Label EVERY sugar (S), phosphate (P), and nitrogen base (A, T, C, G) in the diagram below.
#2
2. Examine the objects inside the box labeled #2. What is this called?
3. What is the special shape of DNA called?
4. Which type of chemical bonds will join the two DNA bases? _
5. Where is DNA found in eukaryotic cells?
6. Which nucleotide part(s) make up the outside of the DNA ladder? (circle all that apply) Sugar
Phosphate
Base
7. Which nucleotide part(s) make up the rungs of the DNA ladder? (circle all that apply) Sugar
Phosphate
Base
DNA Replication (Review your notes on “replication” to help you answer these questions.)
8. Put the pictures of DNA replication in order by placing a 1, 2, or 3 on the line above the picture. (on
the next page)
9. Describe what is happening on the lines below the picture. Be sure to include the names
of any enzyme involved.
10. Replicate this strand of DNA: ACTGCCATTGAC
DNA and RNA Comparison
11. Complete the following chart by comparing DNA, mRNA, and tRNA. Sample answers
have been provided.
DNA
mRNA
tRNA
Deoxyribonucleic
Molecule full name
Acid
Ribose
Name of sugar
Nitrogen Bases
Present
Function
Adenine, Uracil,
Guanine, Cytosine
Store Genetic
information
12. For each statement write DNA, mRNA, or tRNA.
Holds the original coded information for making proteins
Can replicate itself
Copies DNA’s coded message
Carries amino acids to the ribosome for assembly
Found in the nucleus only
Found in the cytoplasm only
Found in both the nucleus and cytoplasm
Carries the coded message to the ribosome
Transcription and Translation: Use the picture to answer the questions 11-13.
13. Describe what is forming and happening in AREA A of the diagram. Include the name of
this process and the key players.
14. Describe what is being gathered and happening in AREA B of the diagram.
15. Describe what is being assembled and happening in AREA C of the diagram. Include the
name of this process and the key players.
16. If a section of code contains 12 bases, how many codons would there be?
17. If a section of code contains 7 codons, how many amino acids would there be?
18. Which mRNA codon will start the process of translation?
19. Which amino acid does every protein begin with?
20. Which mRNA codons will end the process of translation?
21. What bond is formed between amino acids to make a protein?
22. From the DNA information given, fill in the missing information. (Remember to always
use the mRNA to code for the amino acid.)
DNA
mRNA
tRNA
Amino Acid
TTT
23. From the tRNA information given, fill in the missing information.
DNA
mRNA
tRNA
Amino Acid
GUU
24. From the amino acid given, fill in the missing information.
DNA
mRNA
tRNA
Amino Acid
Methionine
25. Follow the rules of transcription and fill in the boxes below? Ask yourself…what does
transcription make?
26. Below is a strand of mRNA. Follow the rules of translation and fill in the tRNA strand
below?
27. Which two amino acids does the following DNA strand code for?
28. Using the codon chart, what codons specify for leucine? List all of them.
PART C: Protein Synthesis Review
Protein synthesis is the process used by the body to make proteins. The first step of protein synthesis is called
Transcription. It occurs in the nucleus. During transcription, mRNA transcribes (copies) DNA. DNA is
“unzipped” and the mRNA strand copies a strand of DNA. Once it does this, mRNA leaves the nucleus and
goes into the cytoplasm. mRNA will then attach itself to a ribosome. The strand of mRNA is then read in order
to make protein. They are read 3 bases at a time. These bases are called codons. tRNA is the fetching puppy.
It brings the amino acids to the ribosome to help make the protein. The 3 bases on tRNA are called anti-codons.
Remember, amino acids are the building blocks for protein. On the mRNA strand, there are start and stop
codons. Your body knows where to start and stop making certain proteins. Just like when we read a sentence,
we know when to start reading by the capitalized word and when to stop by the period.
Ribosome
tRNA
mRNA
mRNA
DNA
PART 1. Answer the following questions on your paper:
1. What is the first step of protein synthesis? _________________________________
2. What is the second step of protein synthesis? _________________________________
3. Where does the first step of protein synthesis occur? _________________________________
4. Where does the second step of protein synthesis occur? ____________________________
5.
Nitrogen bases are read ________ bases at a time.
6. The bases on the mRNA strand are called ______________________.
7. The bases on tRNA are called ______________________.
8. What is the start codon? ______________
9. What are the stop codons? (Use your mRNA chart or pg. 298) _______________________________
10. A bunch of amino acids attached together is called a _____________________________.
PART 2. Use your codon chart to determine the amino acid sequence. Remember to read through the
strand and ONLY start on AUG and STOP when it tells you to stop. Follow example below:
Example:
DNA AGA CGG TAC CTC CGG TGG GTG CTT GTC TGT ATC CTT CTC AGT ATC
mRNA UCU GCC AUG GAG GCC ACC CAC GAA CAG ACA UAG GAA GAG UCA UAG
protein
start - glu – ala –thre – hist – asp –glu – threo - stop
acid
1.
acid
DNA � CCT CTT TAC ACA CGG AGG GTA CGC TAT TCT ATG ATT ACA CGG TTG CGA TCC ATA ATC
mRNA �
protein �
2. DNA � AGA ACA TAA TAC CTC TTA ACA CTC TAA AGA CCA GCA CTC CGA TGA ACT GGA GCA
mRNA �
protein �
3. DNA � TAC CTT GGG GAA TAT ACA CGC TGG CTT CGA TGA ATC CGT ACG GTA CTC GCC ATC
mRNA �
protein �
4. DNA � TAA ACT CGG TAC CTA GCT TAG ATC TAA TTA CCC ATC
mRNA �
protein �
5. DNA � TAC CTT AGT TAT CCA TTG ACT CGA ATT GTG CGC TTG CTG ATC
mRNA �
protein �
Circle the correct choice within the parenthesis for 1 -18.
1. (DNA/RNA) can leave the nucleus.
2. mRNA is made during (transcription/translation).
3. mRNA is made in the (cytoplasm/nucleus).
4. DNA is located in the (nucleus/cytoplasm)
5. (Translation/Transcription) converts DNA into mRNA.
6. (mRNA/rRNA) is used to carry the genetic code from DNA to the ribosomes.
7. (tRNA/rRNA) makes up the ribosome. Look in the book for this.
8. (DNA/RNA) uses uracil instead of thymine.
9. (RNA/amino) acids make up a protein.
11. Transcription takes place in the (nucleus/cytoplasm).
12. tRNA is used in (translation/transcription).
13. tRNA uses (anticodons/codons) to match to the mRNA.
14. Proteins are made at the (nucleus/ribosome).
15. (tRNA/mRNA) attaches the amino acids into a chain.
16. tRNA is found in the (nucleus/cytoplasm).
17. (Translation/Transcription) converts mRNA into a protein.
18. Translation takes place in the (cytoplasm/nucleus).
Fill the Diagram In
DNA
A
mRNA
tRNA
Amino
Acids
C
A
A
G
A
C
G
G
T
A
C
T
G
A
Replication, Transcription & Translation Thinking Questions
1. Draw a DNA nucleotide & an RNA nucleotide. Label each of the 3 major parts.
2. What are the three major differences between DNA & RNA?
a)
b)
c)
3. What is the point of DNA replication? ____________________________
4. When & where does replication occur? _____________________________
5. What is the point of transcription? _______________________________
6. What are three nucleotides together called on mRNA? (ie: ACA)__________
7. The mRNA codons can be used in a chart to find: ____________________
8. What molecule contains an anti-codon? _____________________________
9. Why is this (answer to #13) molecule so important?
10. Translation takes place in the ______________ on a ________________.
11. What is the point of translation?
12. Transcription and translation together is the process of ________________ _______________.