Concept explainers
- a. The isoelectric point (pl) of phenylalanine is pH 5.5. Draw the structure of the major form of phenylalanine at pH values of 1, 5.5, and 11.
- b. The isoelectric point of histidine is pH 7 6. Draw the structures of the major forms of histidine at pH values of 1, 4, 7.6, and 11. Explain why the nitrogen in the histidine ring is a weaker base than the α-amino group.
- c. The isoelectric point of glutamic acid is pH 3.2. Draw the structures of the major forms of glutamic acid at pH values of 1,3.2, 7, and 11. Explain why the side-chain
carboxylic acid is a weaker acid than the acid group next to the α-carbon atom.
(a)
Interpretation:
The structures of the major form of phenylalanine at
Concept introduction:
The more acidic strength increases the formation of the hydrogen ions and decreases the
Answer to Problem 24.27SP
The structures of the major form of phenylalanine at
Explanation of Solution
The structures of the major forms of phenylalanine at
Figure 1
It is conferred from the above reaction that phenylalanine at
(b)
Interpretation:
The structures of the major forms of histidine at
Concept introduction:
The more acidic strength increases the formation of the hydrogen ions and decreases the
Answer to Problem 24.27SP
The structures of the major forms of histidine at
Explanation of Solution
The structures of the major forms of histidine at
Figure 2
It is conferred from the above reaction that histidine at
(c)
Interpretation:
The structures of the major forms of glutamic acid at
Concept introduction:
The more acidic strength increases the formation of the hydrogen ions and decreases the
Answer to Problem 24.27SP
The structures of the major forms of glutamic acid at
Explanation of Solution
The structures of the major forms of glutamic acid at
Figure 3
It is conferred from the above reaction that glutamic acid at
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Chapter 24 Solutions
Organic Chemistry (9th Edition)
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