Indicate how the pKa of the ionizable group of histidine would
be changed in a nonpolar...
Indicate how the pKa of the ionizable group of histidine would
be changed in a nonpolar pocket (increase/decrease) PLEASE EXPLAIN
WHY. I thought it would increase but that's not correct
Histidine has ionizable groups with pKa values of 1.8, 6.0, and
9.2, as shown below. A biochemist makes up 100 mL of a 0.100 M
solution of histidine at a pH of 5.40. She then adds 40 mL of 0.10
M HCl. What is the pH of the resulting solution?
The book answer is 2.4. Please show work to help me understand how
they arrived at this.
A molecule has an ionizable group with a pKa
value of 8. At pH equal to 7.0, estimate roughly how much of the
group is deprotonated (expressed as %)? Use 2 decimal points. Do
not use scientific notation to enter your answer.
All amino acids have two ionizable functional groups: an α-amino
group (average pKa of 9.4) and an α-carboxylic acid group (average
pKa of 2.2). Arginine also has an ionizable side chain (R group)
with a pKa of ~12.5. One of the possible ionization states of
arginine is shown below.
At what pH would the above structure be the predominant
ionization state? Note: Consider the ionization state of all three
of the functional groups.
The protonated form of the R group...
is the pka of a histidine side chain always the same as that of
the free amino acid? Why?
how do titration curves differ between non ionizable and
ionizable r groups? why?
Biochemistry
A nonstandard amino acid has three ionizable groups, with pKa
values of 2.6, 7.4, and 10.13. A 0.1 M solution of this amino acid
is made, 100 ml total, at pH 2.6. To this solution is added 10 ml
of 1 M NaOH. What is the final pH of this solution after the
addition?
A) 3.2
B) 8.0
C) 7.4
D) 6.8
E) 10.13
The pKa of the α-carboxyl group of phenylalanine is 1.83, and
the pKa of its α-amino group is 9.13. Calculate the average net
charge on phenylalanine if it is in a solution that has a pH of
8.30. If the charge is positive, do not enter a + sign.
The pKa of the α-carboxyl group of phenylalanine is 1.83, and
the pKa of its α-amino group is is 9.13.
Calculate the average net charge
on phenylalanine if it is in a solution that has a pH of 8.00 (If
the charge is positive, you do not need to enter a " +"
sign.)
Please show your work.
The pKa of the α-carboxyl group of phenylalanine is 1.83, and
the pKa of its α-amino group is 9.13. Calculate the average net
charge on phenylalanine if it is in a solution that has a pH of
8.20. If the charge is positive, do not enter a + sign.
Draw the structure of protonated histidine and indicate (draw
and name) all possible non bonding interactions with water. include
H bonding, and Hydration Spheres