Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

3. Amino Acids

Isoelectric Point of Amino Acids with Ionizable R-Groups

Biochemistry

3. Amino Acids

Isoelectric Point of Amino Acids with Ionizable R-Groups

Previous problemNext problem

Struggling with Biochemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Electrophoresis separates molecules by migration through a gel only if they have a net charge. How do you expect an amino acid to migrate during electrophoresis when the pH = pI?

Migrate from the (-) end to the (+) end.

Migrate from the (+) end to the (-) end.

No migration.

Previous problemNext problem

Verified step by step guidance

Understand the concept of isoelectric point (pI): The isoelectric point is the pH at which an amino acid has no net charge. At this pH, the positive and negative charges on the amino acid balance each other out.

Consider the behavior of amino acids at their isoelectric point: When the pH of the environment is equal to the pI of the amino acid, the amino acid exists predominantly in its zwitterionic form, meaning it has both positive and negative charges but no overall net charge.

Relate the charge of the amino acid to electrophoresis: Electrophoresis relies on the movement of charged particles through a gel under the influence of an electric field. Molecules with a net charge will migrate towards the electrode of opposite charge.

Predict the migration of the amino acid at pH = pI: Since the amino acid has no net charge at its isoelectric point, it will not experience any force driving it towards either electrode during electrophoresis.

Conclude the expected behavior: Therefore, at pH = pI, the amino acid will not migrate in the electrophoresis gel because it lacks a net charge to be influenced by the electric field.