Find study content
Learning Materials

Discover learning materials by subject, university or textbook.

Explanations

Textbooks

Exams
All Subjects

Anthropology

Archaeology

Architecture

Art and Design

Bengali

Biology

Business Studies

Greek

Chemistry

Chinese

Combined Science

Computer Science

Economics

Engineering

English

English Literature

Environmental Science

French

Geography

German

History

Hospitality and Tourism

Human Geography

Italian

Japanese

Law

Macroeconomics

Marketing

Math

Media Studies

Medicine

Microeconomics

Music

Nursing

Nutrition and Food Science

Physics

Polish

Politics

Psychology

Religious Studies

Sociology

Spanish

Sports Sciences

Translation

All Subjects

Biology

Business Studies

Chemistry

Combined Science

Computer Science

Economics

English

Environmental Science

Geography

History

Math

Physics

Psychology

Sociology

EXAM TYPES

GCSE

IGCSE

AS

A Level

International A Level

University Admissions Tests

GCSE SUBJECTS

GCSE 1

GCSE 2

GCSE 3

GCSE 4

GCSE 5

SOME-TEXT

IGCSE SUBJECTS

IGCSE 1

AS SUBJECTS

AS 1

A Level SUBJECTS

A Level 1

International A Level SUBJECTS

International A Level 1

University Admissions Tests SUBJECTS

University Admissions Tests 1
Features
Features

Discover all of these amazing features with a free account.

Flashcards

Vaia AI

Notes

Study Plans

Study Sets
What’s new?

Flashcards
Study your flashcards with three learning modes.

Study Sets
All of your learning materials stored in one place.

Notes
Create and edit notes or documents.

Study Plans
Organise your studies and prepare for exams.
Resources
Discover

All the hacks around your studies and career - in one place.

Find a job

Find a degree

Student Deals

Magazine

Mobile App
Featured

Magazine
Trusted advice for anyone who wants to ace their studies & career.

Job Board
The largest student job board with the most exciting opportunities.

Vaia Deals
Verified student deals from top brands.

Our App
Discover our mobile app to take your studies anywhere.

Go to App

Learning Materials

Features

Discover

Chapter 19: Q66 (page 762)

Calculate the isoelectric point for each amino acid.
a. cysteine: ${pK}_{a}$ (COOH) = 2.05; ${pK}_{a}$ $(α - {NH}_{3}^{+})$ =10.25
b. methionine: ${pK}_{a}$ (COOH) = 2.28; ${pK}_{a}$ $(α - {NH}_{3}^{+})$ =9.21

Short Answer

Expert verified

a. 6.15

b. 5.75

Step by step solution

01

Step 1:Isoelectric point

The isoelectric point (PI) calculates the pH where charges are balanced. The balanced charges may acquire positive or negative charges in a particular medium.

02

Formula to calculate the PI

The formula to calculate the PI is shown as:

$PI = \frac{{pK}_{1} + {pK}_{2} + {pK}_{3 . . . . . . . . .} + {pK}_{n}}{n}$

03

Step 3:Explanation

a. Isoelectric point of cysteine is calculated as:

$PI = \frac{{pK}_{a} (COOH) + {pK}_{a} (α - {NH}_{3}^{+})}{2} = \frac{2.05 + 10.25}{2} = 6.15 b . Isoelectric point of methionine is calculated as PI = \frac{{pK}_{a} (COOH) + {pK}_{a} (α - {NH}_{3}^{+})}{2} = \frac{2.28 + 9.21}{2} = 5.75$

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

As we will see in Chapter 23, C-H bonds are sometimes more acidic than O-H bonds. Explain why the ${pK}_{a}$ of ${CH}_{2} {(CHO)}_{2}$ is lower than the ${pK}_{a}$ of $OH {({CH}_{2})}_{3} OH$ (9 vs. 16).

Question: Using the ${pk}_{a}$ table in Appendix A, determine whether each of the following bases is strong enough to deprotonate the three compounds listed below. Bases: [1] ${OH}^{-}; [2] {CH}_{3} {CH}_{2}^{-}; [3] {NH}_{2}^{-} [4] CH \equiv C^{-}$

a.

b.

c.

Draw all resonace strucutres of the conjugate bases formed by removal of the labeled protons $(H_{a}, H_{b}, and H_{c})$ in cyclohexane-1,3-dione and acetanilide. For each compound, rank these protons in order of increasing acidity and explain the order you chose.

a.

b.

Question: Identify A–D in the following reactions.

a.

b.

c.

d.

Question: Given the values in Appendix A, which of the following bases are strong enough to deprotonate ${CH}_{3} COOH$ : (a) F ; (b) ${({CH}_{3})}_{3} CO$ ; (c) ${CH}_{3}^{-}; (d) {NH}_{2}^{-} (e) {Cl}^{-}$ ?

See all solutions

Recommended explanations on Chemistry Textbooks

Chemistry Branches

Read Explanation

Physical Chemistry

Read Explanation

Nuclear Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Inorganic Chemistry

Read Explanation

Kinetics

Read Explanation

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free