Organic Chemistry
9th Edition
ISBN: 9781305080485
Author: John E. McMurry
Publisher: Cengage Learning
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Chapter 26.SE, Problem 57AP
Oxytocin, a nonapeptide hormone secreted by the pituitary gland, functions by stimulating uterine contraction and lactation during childbirth. Its sequence was determined from the following evidence:
1. Oxytocin is a cyclic compound containing a disulfide bridge between two cysteine residues.
2. When the disulfide bridge is reduced, oxytocin has the constitution Asn, Cys2, Gln, Gly, Ile, Leu, Pro, Tyr.
3. Partial hydrolysis of reduced oxytocin yields seven fragments:
Asp-Cys, Ile-Glu, Cys-Tyr, Leu-Gly, Tyr-Ile-Glu, Glu-Asp-Cys, and Cys-Pro-Leu.
4. Gly is the C-terminal group.
5. Both Glu and Asp are present as their side-chain amides (Gln and Asn) rather than as free side-chain acids.
What is the amino acid sequence of reduced oxytocin? What is the structure of oxytocin itself?
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Chapter 26 Solutions
Organic Chemistry
Ch. 26.1 - How many of the -amino acids shown in Table 26-1...Ch. 26.1 - Prob. 2PCh. 26.1 - Prob. 3PCh. 26.2 - Hemoglobin has pI=6.8. Does hemoglobin have a net...Ch. 26.3 - Show how you could prepare the following -amino...Ch. 26.3 - What alkyl halides would you use to prepare the...Ch. 26.3 - Prob. 7PCh. 26.4 - There are six isomeric tripeptides that contain...Ch. 26.4 - Draw the structure of M-P-V-G, and indicate its...Ch. 26.5 - Prob. 10P
Ch. 26.5 - Prob. 11PCh. 26.6 - The octapeptide angiotensin II has the sequence...Ch. 26.6 - Prob. 13PCh. 26.6 - Prob. 14PCh. 26.6 - Give the amino acid sequence of hexapeptides that...Ch. 26.7 - Prob. 16PCh. 26.7 - Write all five steps required for the synthesis of...Ch. 26.10 - Prob. 18PCh. 26.SE - Identify the following amino acids:Ch. 26.SE - Prob. 20VCCh. 26.SE - Isoleucine and threonine are the only two amino...Ch. 26.SE - Prob. 22VCCh. 26.SE - Give the sequence of the following tetrapeptide:Ch. 26.SE - Prob. 24MPCh. 26.SE - The chloromethylated polystyrene resin used for...Ch. 26.SE - Prob. 26MPCh. 26.SE - Prob. 27MPCh. 26.SE - Prob. 28MPCh. 26.SE - Except for cysteine, only S amino acids occur in...Ch. 26.SE - Prob. 30APCh. 26.SE - Prob. 31APCh. 26.SE - Show the structures of the following amino acids...Ch. 26.SE - Prob. 33APCh. 26.SE - Using both three- and one-letter codes for amino...Ch. 26.SE - Prob. 35APCh. 26.SE - Show how you could use the acetamidomalonate...Ch. 26.SE - Prob. 37APCh. 26.SE - Show how you could prepare the following amino...Ch. 26.SE - Prob. 39APCh. 26.SE - Predict the product of the reaction of valine with...Ch. 26.SE - Prob. 41APCh. 26.SE - Prob. 42APCh. 26.SE - Propose two structures for a tripeptide that gives...Ch. 26.SE - Show the steps involved in a synthesis of...Ch. 26.SE - Prob. 45APCh. 26.SE - Prob. 46APCh. 26.SE - Prob. 47APCh. 26.SE - Which of the following amino acids are more likely...Ch. 26.SE - Leuprolide is a synthetic nonapeptide used to...Ch. 26.SE - The -helical parts of myoglobin and other proteins...Ch. 26.SE - Prob. 51APCh. 26.SE - Cytochrome c is an enzyme found in the cells of...Ch. 26.SE - Prob. 53APCh. 26.SE - Prob. 54APCh. 26.SE - Prob. 55APCh. 26.SE - What is the structure of a nonapeptide that gives...Ch. 26.SE - Oxytocin, a nonapeptide hormone secreted by the...Ch. 26.SE - Aspartame, a nonnutritive sweetener marketed under...Ch. 26.SE - Prob. 59APCh. 26.SE - Prob. 60APCh. 26.SE - Prob. 61APCh. 26.SE - Prob. 62AP
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