(a)
Interpretation:
The structure of C from the given illustration and the explanation for how it is obtained is to be stated.
Concept introduction:
Trypsin is an enzyme that is found in the
Answer to Problem 27.53AP
The structure of C from the given illustration is
Explanation of Solution
The molecular mass of amino acid
Figure 1
As a result, the phenyl hydantoin derivative is not formed. Due to this, the peptide C remain unchanged on Edman degradation. When the peptide C reacts with trypsin enzyme, it forms a single peptide D. Also, the trypsin enzyme cleaves at lysine and arginine residue. The peptide D gives the same amino acid analysis as peptide C. This confirms that the peptide D does not contain arginine residue, due to this the amino acid analysis of the peptide C is similar to that of the peptide D. The partial structure of peptide D is found to be
The structure of C from the given illustration is
(b)
Interpretation:
The b-type fragmentation for
Concept introduction:
In mass spectroscopy, compounds can be identified on the basis of the mass of the compound. When the compound breaks into fragment then they can be distinguished from the other compounds. This technique is also used to differentiate the isotopes of compounds. In amino acids, three types of fragments are observed in low energy collisions are a, b and y ions. It is known as tandem mass spectrometry.
Answer to Problem 27.53AP
The b-type fragmentation for
The b-type fragmentation for
where
Explanation of Solution
In amino acids, b-type fragments appear due to an amino group or in other words charge is being carried by N-terminal. That is why it is also known as the N-terminus amino acid fragment. The b-type fragment is shown below.
Figure 2
The peptide C is
The peptide D is
The b-type fragmentation for
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Chapter 27 Solutions
EBK ORGANIC CHEMISTRY
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