Textbook Question
Consider the amino acids glycine, proline, and lysine.
b. Using three-letter abbreviations for the amino acids, give the sequence for each of the possible tripeptides.
Ch.10 Proteins Workers of the Cell
Frost4th EditionGeneral, Organic and Biological ChemistryISBN: 9780134988696
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Table of contents
- Ch.4 Introduction to Organic Compounds75
- Ch.5 Chemical Reactions19
- Ch.6 Carbohydrates Life's Sweet Molecules62
- Ch.7 States of Matter and Their Attractive Forces8
- Ch.8 Solution Chemistry Sugar and Water Do Mix4
- Ch.10 Proteins Workers of the Cell89
- Ch.11 Nucleic Acids Big Molecules with a Big Role69
- Ch.12 Food as Fuel An Overview of Metabolism65
Frost4th EditionGeneral, Organic and Biological ChemistryISBN: 9780134988696Not the one you use?Change textbook
Chapter 6, Problem 57c
Give the name and three-letter abbreviation for the amino acid described by each of the following:
c. the polar amino acid with a sulfur atom in its side chain
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Identify the amino acids that are classified as polar. Polar amino acids have side chains that can form hydrogen bonds or interact with water due to their partial charges.
Determine which polar amino acids contain a sulfur atom in their side chain. Sulfur is a key element to look for in the structure of the amino acid.
Recall that cysteine and methionine are the two amino acids that contain sulfur. However, methionine is nonpolar, so it does not meet the criteria of being polar.
Conclude that the polar amino acid with a sulfur atom in its side chain is cysteine. Its side chain contains a thiol group (-SH), which contributes to its polarity.
Provide the name and three-letter abbreviation for cysteine: the name is 'cysteine,' and the three-letter abbreviation is 'Cys.'
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Polar Amino Acids
Polar amino acids are those that have side chains capable of forming hydrogen bonds with water, making them hydrophilic. These amino acids typically contain functional groups such as hydroxyl (-OH), carboxyl (-COOH), or amine (-NH2) groups. Their polarity allows them to interact with the aqueous environment of cells, playing crucial roles in protein structure and function.
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Polar Amino Acids Concept 2
Amino Acid Structure
Amino acids are organic compounds that serve as the building blocks of proteins. Each amino acid consists of a central carbon atom, an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R group) that determines the specific properties of the amino acid. The side chain can vary in size, charge, and polarity, influencing the amino acid's role in protein structure.
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Cysteine
Cysteine is a polar amino acid characterized by the presence of a sulfur atom in its side chain, represented by the three-letter abbreviation 'Cys.' The sulfur atom allows cysteine to form disulfide bonds with other cysteine residues, which are important for stabilizing the three-dimensional structure of proteins. This unique property makes cysteine essential in various biological processes, including enzyme function and protein folding.
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Related Practice
Textbook Question
Indicate whether each of the following describes a competitive or a noncompetitive inhibitor.
e. Adding more substrate to the reaction restores the enzyme activity.
Textbook Question
Give the name and three-letter abbreviation for the amino acid described by each of the following:
a. the nonpolar amino acid with a sulfur atom in its side chain
Textbook Question
Give the name and three-letter abbreviation for the amino acid described by each of the following:
a. the polar amino acid with a benzene ring in its side chain
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.
Textbook Question
Draw the structure of the possible dipeptides formed from one alanine combining with one cysteine.