The structure of
at the isoelectric point is:
A)
D)
B)
E)
C)
Question 2The isoelectric pH (pI) of
is likely to be at a pH that is
A)
below p
K1.
B)
at p
K1.
C)
between p
K1 and p
K2.
D)
at p
K2.
E)
above p
K2.
Question 3At the isoelectric point, the structure of methionine (2-amino-4-methylthiobutanoic acid) is:
A)
D)
B)
E)
C)
Question 4Based on the equilibria shown below, what is the net charge on structure IV?
A)
2
B)
1
C)
0
D)
+1
E)
+2
Question 5Which of the following will migrate toward the positive electrode in an electrophoresis experiment?
A)
I
B)
II
C)
III
D)
I and III
E)
none will migrate
Question 6Based on the p
Ka's of aspartic acid shown below, what is its approximate isoelectric point?
A)
2
B)
3
C)
5
D)
7
E)
10
Question 7If an amino acid has one carboxyl group and one amino group, and the p
Ka's are 2.4 and 9.8 respectively, what is its isoelectric point?
A)
3.7
B)
6.1
C)
7.0
D)
7.9
E)
12.2