Biochemistry: Concepts and Connections (2nd Edition)
2nd Edition
ISBN: 9780134641621
Author: Dean R. Appling, Spencer J. Anthony-Cahill, Christopher K. Mathews
Publisher: PEARSON
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Chapter 2, Problem 18P
Histidine is an amino acid with three titratable groups: an -NH3+ group (pKa = 9.2) —COOH group (pKa = 1.8). and an imidazole (
a. Identify which point on the titration curve corresponds to the pKa for each of the titratable groups, and which point corresponds to the pl. Explain your choices.
b. Calculate the value of pl for histidine.
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Histidine is an amino acid with three titratable groups: an -NH3+ group (pKa = 9.2), a -COOH group (pKa = 1.8), and an imidazole (amine-like) group (pKa = 6.0). The titration curve for histidine is shown below with four points highlighted. (a) Identify which point on the titration curve corresponds to the pKa for each of the titratable groups, and which point corresponds to the pI. Explain your choices. (b) Calculate the value of pI for histidine
E. Histidine is an amino acid with three titratable groups: an -NH," group
(pK, = 9.2), a -COOH group (pK, = 1.8), and an imidazole (amine-
like) group (pK, = 6.0). The titration curve for histidine is shown below
with four points highlighted.
(a) Identify which point on the titration curve corresponds to the pK, for
each of the titratable groups, and which point corresponds to the pl.
Explain your choices.
(b) Calculate the value of pl for histidine.
14
12
10
6.
4
2-
2
3
Moles "OH added per mole histidine
на
Sketch the titration curve for the amino acid alanine with pka1 = 2.34 and pka2 = 9.69.
Chapter 2 Solutions
Biochemistry: Concepts and Connections (2nd Edition)
Ch. 2 - Suppose a chloride ion and a sodium ion are...Ch. 2 - Draw two different possible hydrogen-bonding...Ch. 2 - Prob. 3PCh. 2 - 4. What is the pH of each of the following...Ch. 2 - Prob. 5PCh. 2 - The weak acid HA is 2% ionized (dissociated) in a...Ch. 2 - 7. Calculate the pH values and draw the titration...Ch. 2 - What is the pH of the following buffer mixtures?...Ch. 2 - a. Suppose you wanted to make a buffer of exactly...Ch. 2 - Prob. 10P
Ch. 2 - You need to make a buffer whose pH is 7.0, and you...Ch. 2 - Describe the preparation of 2.00 L of 100 glycine...Ch. 2 - Carbon dioxide is dissolved in blood (pH 7.4) to...Ch. 2 - What is the molecular basis for the observation...Ch. 2 - The anno acid arginine ionizes according to the...Ch. 2 - It is possible to make a buffer that functions...Ch. 2 - A student is carrying out a biological preparation...Ch. 2 - Histidine is an amino acid with three titratable...Ch. 2 - Prob. 19PCh. 2 - A biochemical reaction takes place in a 1.00 ml...Ch. 2 - Is RNA-binding enzyme RNase A more likely to have...Ch. 2 - Consider a protein in which a negatively charged...Ch. 2 - Prob. 23PCh. 2 - Prob. 24P
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