Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

18. Amino Acids and Proteins

Peptides

GOB Chemistry

18. Amino Acids and Proteins

Peptides

Previous problemNext problem

4:43 minutes

Problem 60d

Textbook Question

Aspartame, which is commonly known as NutraSweet™, contains the following dipeptide:

d. Draw the structure of the isomer of this dipeptide where the C-terminal and N-terminal amino acids are switched.

Verified step by step guidance

Understand the structure of a dipeptide: A dipeptide consists of two amino acids linked by a peptide bond. The N-terminal amino acid has a free amino group (-NH2), and the C-terminal amino acid has a free carboxyl group (-COOH).

Identify the original structure of the dipeptide in Aspartame: The dipeptide in Aspartame is composed of phenylalanine and aspartic acid. Determine which amino acid is at the N-terminal and which is at the C-terminal in the given structure.

Switch the positions of the amino acids: To create the isomer, reverse the positions of the N-terminal and C-terminal amino acids. This means the amino acid that was originally at the N-terminal will now be at the C-terminal, and vice versa.

Redraw the peptide bond: Ensure that the peptide bond (-CO-NH-) is correctly formed between the carboxyl group of the new N-terminal amino acid and the amino group of the new C-terminal amino acid.

Verify the structure: Double-check that the new structure maintains the correct connectivity of atoms and functional groups, and that the amino acids are properly oriented with their side chains intact.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Dipeptides

Dipeptides are molecules formed by the condensation of two amino acids, linked by a peptide bond. The sequence and identity of the amino acids determine the properties and function of the dipeptide. Understanding the structure of dipeptides is crucial for analyzing their behavior in biological systems, including their role in sweeteners like aspartame.

Isomerism

Isomerism refers to the phenomenon where two or more compounds have the same molecular formula but different structural arrangements. In the context of dipeptides, switching the C-terminal and N-terminal amino acids creates an isomer, which can have different properties and biological activities. Recognizing isomers is essential for understanding how slight changes in structure can affect function.

Amino Acid Structure

Amino acids are the building blocks of proteins, each consisting of a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and a variable R group. The specific arrangement of these groups determines the identity and characteristics of the amino acid. Knowledge of amino acid structures is vital for drawing and manipulating peptide structures, including dipeptides.

Watch next

Master Peptides Concept 1 with a bite sized video explanation from Jules

Start learning