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Ch.10 Proteins Workers of the Cell
Frost - General, Organic and Biological Chemistry 4th Edition
Frost4th EditionGeneral, Organic and Biological ChemistryISBN: 9780134988696Not the one you use?Change textbook
All textbooksFrost 4th EditionCh.10 Proteins Workers of the CellProblem 18d
Chapter 6, Problem 18d

Draw the structural formula for each of the following peptides:
d. IYP

Verified step by step guidance
1
Step 1: Understand the problem. The peptide 'IYP' consists of three amino acids: Isoleucine (I), Tyrosine (Y), and Proline (P). Peptides are formed by linking amino acids through peptide bonds, which are covalent bonds between the carboxyl group of one amino acid and the amino group of the next.
Step 2: Begin by drawing the backbone structure of the peptide. Each amino acid has a central carbon atom (α-carbon) bonded to an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a unique side chain (R-group). Arrange the amino acids in the order Isoleucine, Tyrosine, and Proline.
Step 3: Connect the amino acids using peptide bonds. A peptide bond is formed when the carboxyl group of one amino acid reacts with the amino group of the next amino acid, releasing a molecule of water (condensation reaction). Draw the peptide bond between Isoleucine and Tyrosine, and then between Tyrosine and Proline.
Step 4: Add the side chains (R-groups) for each amino acid. Isoleucine has a branched alkyl group, Tyrosine has a phenol group, and Proline has a cyclic structure where the side chain connects back to the amino group. Ensure the side chains are correctly attached to the α-carbon of each amino acid.
Step 5: Verify the structure. Ensure the peptide backbone is continuous, the peptide bonds are correctly formed, and the side chains are accurately represented. The final structure should show the sequence Isoleucine-Tyrosine-Proline with all atoms and bonds clearly depicted.

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Key Concepts

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

Peptide Structure

Peptides are short chains of amino acids linked by peptide bonds. The structure of a peptide is determined by the sequence of its constituent amino acids, which influences its properties and functions. Understanding the basic structure of peptides is essential for drawing their structural formulas.
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Peptides Concept 1

Amino Acids

Amino acids are the building blocks of peptides and proteins, each containing an amino group, a carboxyl group, and a unique side chain (R group). The specific sequence of amino acids in a peptide determines its identity and characteristics. For the peptide IYP, the amino acids involved are Isoleucine, Tyrosine, and Proline.
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Amino Acid Catabolism: Amino Group Example 2

Structural Formula Representation

The structural formula of a peptide visually represents the arrangement of atoms and the bonds between them. It includes the backbone formed by the peptide bonds and the side chains of the amino acids. Accurately drawing the structural formula requires knowledge of chemical bonding and the specific structures of the involved amino acids.
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Related Practice
Textbook Question

Identify the N-terminus and the C-terminus for each of the peptides in Problem 10.18.

d. IYP

Textbook Question

Identify the N-terminus and the C-terminus for each of the peptides in Problem 10.18.

c. Val—Arg

Textbook Question

Draw the structural formula for each of the following peptides:

c. His—Met—Gln

Textbook Question

Identify the N-terminus and the C-terminus for each of the peptides in Problem 10.18.

a. Ala—Asn—Thr

b. DS

Textbook Question

Draw the structural formula for each of the following peptides:

b. KCG

Textbook Question

Draw the structural formula for each of the following peptides:

c. Val—Arg