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DNA - Problem Set #4
1.
Write the DNA complement for 5'-ACCGTTAAT-3'
2.
Write the mRNA complement for 5'-ACCGTTAAT-3'
3.
Aspartic acid and glutamic acid have carboxyl groups on their side chains and are
called acidic amino acids. Compare the codons for these two amino acids.
H
O
H
O
H N CH C OH
H N CH C OH
CH2
CH2
Aspartic Acid
O
Glutamic Acid
CH2
OH
O
OH
4.
Compare the structures of phenylalanine and tyrosine. Compare the codons for
these two amino acids.
H
O
H
O
H N CH C OH
H N CH C OH
CH2
CH2
Phenylalanine
Tyrosine
OH
6.
During transcription, a portion of mRNA is synthesized with the following base
sequence:
5'-AUG-GUA-CCA-CAU-UUG-UGA-3'
a) Write the nucleotide sequence of the DNA from which this portion of mRNA was
synthesized.
DNA
mRNA
5'-AUG-GUA-CCA-CAU-UUG-UGA-3'
b) Write the primary sequence of the polypeptide coded by this section of mRNA.
7. Methionine is the first amino acid incorporated into the heptapeptide specified by
the following mRNA:
5'-G-C-A-U-G-G-A-C-C-C-C-G-U-U-A-U-U-A-A-A-C-A-C-3'
What is the sequence of amino acids in the peptide?
Give the sequences of bases in DNA that resulted in the mRNA.
List the codons in mRNA that specify each amino acid and the anticodons of tRNA
that carry each amino acid.
8.
Consider the following amino acids:
H H O
H H O
H H O
H H O
H N C C O H H N C C O H H N C C O H H N C C O H
H
CH2
CH2
CH2
CH2
Gly
Phe
Tyr
Met
S
CH3
OH
Hydrolysis of the pentapeptide opiate met-enkephalin (which has a C-terminal methionine
residue and 2 Gly) gave the following fragments:
Phe•Met
Tyr•Gly
Gly•Phe
What is the sequence of amino acids in met-enkephalin??
Draw out the structure of met-enkephalin.
Give an mRNA sequence that would code for the synthesis of met-enkephelin:
DNA
DNA
mRNA
A
U
G
C
C
G
T
U
mRNA