Chapter 21: Q13P (page 996)

a. What percentage of the $α$ -amino group of lysine will be protonated at its pI?<25%50% >75%
b. Answer the same question for the $ε$ -amino group of lysine.

Short Answer

Expert verified

>75%
>75%

Step by step solution

Step-by-Step SolutionStep 1:Structure of Lysine

The structure of Lysine is shown below:

Structure of Lysine

Step 2:α-amino and ε-amino group of lysine

Lysine is an amino acid with 3 ionisable side groups which are $α$ -COOH, $α$ -amino and $ε$ -amino.There pKa values are 2.2, 9.2, 10.8, respectively. Thus, isoelectric point can be calculated as:

$pI= \frac{9.2+10.8}{2} =10$

Thus, percentage of the $α$ amino group of lysine will be protonated and its pI will be,

$\frac{9.2}{10} \times 100$ = 92%

And, percentage of $ε$ amino group of lysine will be more than 75%.

Hence,more than 75% of $α$ -amino group and $ε$ -amino group will be protonated at its pI.

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a. What percentage of the $α$ -amino group of lysine will be protonated at its pI?<25%50% >75%
b. Answer the same question for the $ε$ -amino group of lysine.

Short Answer

Step by step solution

Step-by-Step SolutionStep 1:Structure of Lysine

Step 2:α-amino and ε-amino group of lysine

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a. What percentage of the α-amino group of lysine will be protonated at its pI?<25%50% >75%b. Answer the same question for theε-amino group of lysine.

Short Answer

Step by step solution

Step-by-Step SolutionStep 1:Structure of Lysine

Step 2:α-amino and ε-amino group of lysine

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Chemistry Textbooks

Nuclear Chemistry

Chemical Reactions

Ionic and Molecular Compounds

Organic Chemistry

Making Measurements

The Earths Atmosphere

Study anywhere. Anytime. Across all devices.

a. What percentage of the $α$ -amino group of lysine will be protonated at its pI?<25%50% >75%
b. Answer the same question for the $ε$ -amino group of lysine.