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Name:
TEST REVIEW: MAKING PROTEINS
1. What day is your test?
MARCH 19TH
2. Name four scientists and explain their contributions to the discovery of DNA.
Rosalind Franklin- gave an xray picture to Watson and Crick
Watson and Crick- hypothesized the double helix
Erwin Chargaff- determined how the bases pair together a/t and g/c
3. Describe the structure of a protein.
Nucleic acids are a chain of amino acids
4. Describe the similarities and differences between DNA and RNA.
DNA and RNA are both nucleic acids. DNA is double stranded. RNA is single stranded. DNA uses the
nitrogen bases ATGC. RNA uses the nitrogen bases AUCG
5. What is transcription? Where does it take place?
Transcription is the process of creating an mRNA strand from a DNA strand. It takes place in the
nucleus.
6. What is translation? Where does it take place?
Translation is the process of making a protein from an mRNA strand. It takes place on ribosomes in
the cytoplasm.
7. Where does protein synthesis occur?
Protein synthesis occurs in the cytoplasm on a ribosome.
8. Transcribe the DNA strand TAG ACG GGG CCC AAA
Transcribe means make mRNA: AUC UGC CCC GGG UUU
9. Translate the mRNA strand from number 8.
Translate means make a protein (an amino acid chain.)
isoleucine-cysteine-proline-glycine-phenylalanine
10. What is a point mutation?
A change in a DNA strand of only one nucleotide.
11. When is a mutation harmful?
When it creates a different amino acid.
12. When is a mutation neutral?
When the amino acid sequence does not change.
13. What is a frameshift mutation?
When a nucleotide is inserted or deleted and the wrong three nucleotide sequence is read.
14. Consider the DNA strand TAG GCC CAG GTT AGT
a. If the first G is changed to a C, will it be a harmful or a neutral mutation? Explain.
original: TAG GCC CAG GTT AGT
mutated: TAC GCC CAG GTT AGT
mRNA: AUC CGG GUC CAA UCA
mutated: AUG CGG GUC CAA UCA
AA:
iso-arg-val-glut-ser
mutated: met-arg-val-glut-ser
HARMFUL BECAUSE IT CHANGED THE AMINO ACIDS
a. If the first C is deleted, will it be a harmful or a neutral mutation? Explain.
original: TAG GCC CAG GTT AGT
mutated: TAC GC CAG GTT AGT
mRNA: AUC CGG GUC CAA UCA
mutated: AUG CGG UCC AAU CA
AA:
iso-arg-val-glut-ser
mutated: met-arg-ser-aspHARMFUL BECAUSE IT CHANGED THE AMINO ACIDS
15. What is gel electrophoresis? How does it help catch criminals?
Gel electrophoresis is a process used to separate DNA according to its size. Enzymes are used to
cut up the molecule. This can help make a DNA fingerprint to compare a suspect’s DNA to DNA found at a
crime scene. If the bands match, the criminal was present at the crime scene.