Organic Chemistry 6th Edition solutions

Organic Chemistry 6
The following section of DNA codes for oxytocin, a polypeptide hormone. 39ACG-ATA-TAA-GTT-TTA- ACG-GGA-GAA-CCA-ACT-59 (a) Write the base sequence of the mRNA synthesized from this section of DNA. (b) Given the sequence of bases in part (a), write the primary structure of oxytocin.

Organic Chemistry 6
The following is another section of the bovine rhodopsin gene. Which of the endonucleases given in Example 28.6 will catalyze cleavage of this section? 59- ACGTCGGGTCGTCGTCCTCTCGCGGTGGTGAGTCTTCCGGCTCTTCT-39

Organic Chemistry 6
A pioneer in designing and synthesizing antimetabolites that could destroy cancer cells was George Hitchings at the Burroughs Wellcome Company. In 1942, he initiated a program to discover DNA antimetabolites, and in 1948, he and Gertrude Elion synthesized 6-mercaptopurine, a successful drug for treat

Organic Chemistry 6
Following are structural formulas for cytosine and thymine. Draw two additional tautomeric forms for cytosine and three additional tautomeric forms for thymine. N NH2 O N H Cytosine (C) HN CH3 O O N H Thymine (T)

Organic Chemistry 6
Draw a structural formula for a nucleoside composed of the following. (a) a-d-Ribose and adenine (b) b-2-Deoxy-d-ribose and cytosine

Organic Chemistry 6
Nucleosides are stable in water and in dilute base. In dilute acid, however, the glycosidic bond of a nucleoside undergoes hydrolysis to give a pentose and a heterocyclic aromatic amine base. Propose a mechanism for this acid-catalyzed hydrolysis.

Organic Chemistry 6
Explain the difference in structure between a nucleoside and a nucleotide.

Organic Chemistry 6
Draw a structural formula for each nucleotide, and estimate its net charge at pH 7.4, the pH of blood plasma. (a) 29-Deoxyadenosine 59-triphosphate (dATP) (b) Guanosine 39-monophosphate (GMP) (c) 29-Deoxyguanosine 59-diphosphate (dGDP)

Organic Chemistry 6
Cyclic-AMP, fi rst isolated in 1959, is involved in many diverse biological processes as a regulator of metabolic and physiological activity. In it, a single phosphate group is esterifi ed with both the 39 and 59 hydroxyls of adenosine. Draw a structural formula of cyclic-AMP.

Organic Chemistry 6
Why are deoxyribonucleic acids called acids? What are the acidic groups in their structure?

Organic Chemistry 6
Human DNA contains approximately 30.4% A. Estimate the percentages of G, C, and T and compare them with the values presented in Table 28.1

Organic Chemistry 6
Draw a structural formula of the DNA tetranucleotide 59-A-G-C-T-39. Estimate the net charge on this tetranucleotide at pH 7.0. What is the complementary tetranucleotide to this sequence?

Organic Chemistry 6
List the postulates of the Watson-Crick model of DNA secondary structure.

Organic Chemistry 6
The Watson-Crick model is based on certain experimental observations of base composition and molecular dimensions. Describe these observations and show how the Watson-Crick model accounts for each.

Organic Chemistry 6
If you read J. D. Watsons account of the discovery of the structure of DNA, The Double Helix, you will fi nd that for a time in their model-building studies, he and Crick were using alternative (and incorrect, at least in terms of their fi nal model of the double helix) tautomeric structures for some

Organic Chemistry 6
Compare the a-helix of proteins and the double helix of DNA in these ways. (a) The units that repeat in the backbone of the polymer chain. (b) The projection in space of substituents along the backbone (the R groups in the case of amino acids; purine and pyrimidine bases in the case of double-strande

Organic Chemistry 6
Discuss the role of the hydrophobic interactions in stabilizing the following. (a) Double-stranded DNA (b) Lipid bilayers (c) Soap micelles

Organic Chemistry 6
Name the type of covalent bond(s) joining monomers in these biopolymers. (a) Polysaccharides (b) Polypeptides (c) Nucleic acids

Organic Chemistry 6
In terms of hydrogen bonding, which is more stable, an A-T base pair or a G-C base pair?

Organic Chemistry 6
At elevated temperatures, nucleic acids become denatured, that is they unwind into single-stranded DNA. Account for the observation that the higher the G-C content of a nucleic acid, the higher the temperature required for its thermal denaturation

Organic Chemistry 6
Write the DNA complement for 59-ACCGTTAAT-39. Be certain to label which is the 59 end and which is the 39 end of the complement strand.

Organic Chemistry 6
Write the DNA complement for 59-TCAACGAT-39.

Organic Chemistry 6
Compare the degree of hydrogen bonding in the base pair A-T found in DNA with that in the base pair A-U found in RNA.

Organic Chemistry 6
Compare DNA and RNA is these ways. (a) Monosaccharide units (b) Principal purine and pyrimidine bases (c) Primary structure (d) Location in the cell (e) Function in the cell

Organic Chemistry 6
What type of RNA has the shortest lifetime in cells?

Organic Chemistry 6
Write the mRNA complement for 59-ACCGTTAAT-39. Be certain to label which is the 59 end and which is the 39 end of the mRNA strand.

Organic Chemistry 6
Write the mRNA complement for 59-TCAACGAT-39

Organic Chemistry 6
What does it mean to say that the genetic code is degenerate?

Organic Chemistry 6
Write the mRNA codons for the following. (a) Valine (b) Histidine (c) Glycine

Organic Chemistry 6
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.

Organic Chemistry 6
Compare the structural formulas of the aromatic amino acids phenylalanine and tyrosine. Compare also the codons for these two amino acids.

Organic Chemistry 6
Glycine, alanine, and valine are classifi ed as nonpolar amino acids. Compare their codons. What similarities do you fi nd? What differences do you fi nd?

Organic Chemistry 6
Codons in the set CUU, CUC, CUA, and CUG all code for the amino acid leucine. In this set, the fi rst and second bases are identical, and the identity of the third base is irrelevant. For what other sets of codons is the third base also irrelevant, and for what amino acid(s) does each set code?

Organic Chemistry 6
Compare the codons with a pyrimidine, either U or C, as the second base. Do the majority of the amino acids specifi ed by these codons have hydrophobic or hydrophilic side chains?

Organic Chemistry 6
Compare the codons with a purine, either A or G, as the second base. Do the majority of the amino acids specifi ed by these codons have hydrophilic or hydrophobic side chains?

Organic Chemistry 6
What polypeptide is coded for by this mRNA sequence?

Organic Chemistry 6
The alpha chain of human hemoglobin has 141 amino acids in a single polypeptide chain. Calculate the minimum number of bases on DNA necessary to code for the alpha chain. Include in your calculation the bases necessary for specifying termination of polypeptide synthesis.

Organic Chemistry 6
In HbS, the human hemoglobin found in individuals with sickle-cell anemia, glutamic acid at position 6 in the beta chain is replaced by valine. (a) List the two codons for glutamic acid and the four codons for valine. (b) Show that one of the glutamic acid codons can be converted to a valine codon by