Skip to main content
Pearson+ LogoPearson+ Logo
Ch.16 Amino Acids, Proteins, and Enzymes
Timberlake - Chemistry: An Introduction to General, Organic, and Biological Chemistry 14th Edition
Timberlake14thChemistry: An Introduction to General, Organic, and Biological ChemistryISBN: 9781292472249Not the one you use?Change textbook
Chapter 16, Problem 11c

Draw the condensed structural formula for each of the following peptides, and give its three-letter and one-letter abbreviations:
c. glycylalanylvaline

Verified step by step guidance
1
Step 1: Understand the peptide structure. A peptide is a chain of amino acids linked by peptide bonds. In this case, the peptide consists of three amino acids: glycine (Gly), alanine (Ala), and valine (Val), in that order.
Step 2: Write the condensed structural formula for glycine (Gly). Glycine has the simplest structure among amino acids: H₂N-CH₂-COOH. When it forms a peptide bond, the -COOH group reacts with the -NH₂ group of the next amino acid.
Step 3: Write the condensed structural formula for alanine (Ala). Alanine has the structure H₂N-CH(CH₃)-COOH. When it is part of a peptide, its -NH₂ group forms a bond with the -COOH group of the previous amino acid, and its -COOH group bonds with the -NH₂ group of the next amino acid.
Step 4: Write the condensed structural formula for valine (Val). Valine has the structure H₂N-CH(CH(CH₃)₂)-COOH. In the peptide, its -NH₂ group forms a bond with the -COOH group of the previous amino acid, and its -COOH group remains free at the end of the chain.
Step 5: Combine the structures to form the peptide glycylalanylvaline. The condensed structural formula is written by linking the amino acids through peptide bonds (-CONH-). The three-letter abbreviation for the peptide is Gly-Ala-Val, and the one-letter abbreviation is GAV.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

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 how to represent peptides structurally is essential for visualizing their molecular composition.
Recommended video:
Guided course
3:07
Peptides Concept 1

Amino Acid Abbreviations

Amino acids are the building blocks of peptides and proteins, each having a unique three-letter and one-letter abbreviation. For example, glycine is abbreviated as Gly (three-letter) and G (one-letter). Familiarity with these abbreviations is crucial for efficiently communicating and writing about peptides in biochemistry.
Recommended video:
Guided course
3:03
Amino Acid Catabolism: Amino Group Example 2

Condensed Structural Formula

A condensed structural formula provides a simplified representation of a molecule, showing the arrangement of atoms without depicting all bonds explicitly. In the context of peptides, it illustrates how amino acids are connected, allowing for a clear understanding of the peptide's structure and composition.
Recommended video:
Guided course
1:53
Condensed Formula Concept 1