Download DNA, RNA and the Genetic Code Worksheet

Biology 160
DNA Lab
Names_________________________________
_________________________________
Lab Section: 1:00 pm
3:00 pm
DNA, RNA and the Genetic Code Worksheet
(complete & turn in during the lab period! – work together (in pairs) on this lab)
Write the term that matches each phrase
DNA and RNA are types of…
______________________________
Pyrimidine that pairs with adenine, in DNA
______________________________
Purine that pairs with cytosine, in DNA or RNA
______________________________
Chemical bonds that join complementary nitrogen bases
______________________________
Two molecules forming sides of the DNA “ladder”
______________________________
In DNA replication, what determines the sequence of nucleotides in the new strands of nucleotides that
form?
Fill in the sequence of complementary bases on the unlabeled strands below, for the two different
situations.
DNA replication:
T A C G C T A G T C A G A T T
mRNA production:
T A C G C T A G T C A G A T T
Comparison of DNA and RNA molecules:
DNA
RNA
number of nucleotide strands
nitrogenous base that is
complimentary to “A”
type of sugar in the
“backbone” of the polymer
number of different types
location(s) in a cell where it
can be found
includes portions called
“codons” and “anticodons”
(yes or no)
Do enzymes play important
roles in building the
molecule?
(yes or no)
Using the following five term: mRNA, Translation, Protein, DNA, Transcription fill in
the blanks and arrows in the diagram to show the flow of genetic information:
Bio160
DNA Lab
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Fill in the blanks in the following statement, being as specific as possible:
The process of ________________ copies information from ________________ to ________________.
The process of ________________converts a sequence of ________________ to a sequence of
________________, which forms a protein.
Write the term that matches each statement:
carries the genetic code out of the nucleus
__________________________
specifies a particular amino acid
__________________________
sites of protein synthesis
__________________________
carries amino acids to ribosomes
__________________________
tRNA triplet that pairs with codon
__________________________
codon that starts polypeptide synthesis
__________________________
codons that stop polypeptide synthesis
__________________________
Indicate the tRNA anticodons and the DNA base triplets associated with each amino acid described
below. Then for the amino acid Val (valine) fill in two other possibilities.
Amino Acid
tRNA anticodon
mRNA codon
DNA base triplet
Trp
Lys
Met
Val
Val
Val
____________
____________
____________
____________
____________
____________
UGG
AAA
AUG
GUU
____________
____________
____________
____________
____________
____________
____________
____________
The string of letters below represents one strand of DNA. First, transcribe the DNA strand into the mRNA
sequence that would be produced from it. Then, identify the mRNA reading frame and draw vertical
lines between the mRNA bases to separate the sequence into codons. Finally, use the genetic code table
to determine the sequence of amino acids in the protein that would be produced from the mRNA strand
TACTCCGATCATCCCTGCAGTTACGAATCGCGTGTGTAACCTGAAGTAACT
mRNA:
Amino Acids: ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____
Bio160
DNA Lab
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The following is another hypothetical strand of DNA. We’ll use this first template to explore the impact
of mutations (arrows indicate the site of the mutations): translate the mRNA sequence, just as a
ribosome would, to produce an amino acid sequence of a polypeptide chain.
ORIGINAL DNA SEQUENCE i.e. non-mutant gene:
DNA:
T A C A G G C C G C A A T T T G A G A T T
mRNA:
AA:
Base substitution #1
DNA:
T A C A G G C C G C A A T T T G T G A T T
mRNA:
AA:
Base Substitution #2
DNA:
T A C A G G C C G G A A T T T G T G A T T
mRNA:
AA:
Triplet Deletion
DNA:
T A C A G G C C G T T T G T G A T T
mRNA:
AA:
Base deletion
DNA:
T A C A G G C C G C A A T T G A G A T T
mRNA:
AA:
Base Addition
DNA: T A C A G G C C G C A T A T T T G A G A T T
mRNA:
AA:
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DNA Lab
Page 4 of 5
Which mutation had the least amount of effect on the protein structure? Why?
Which mutation had the largest effect on the protein structure? Why?
Explain how DNA ultimately controls the functioning of cells (be specific!), and how/why mutations in
DNA can disrupt proper functioning.
Bio160
DNA Lab
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