Podcast
Questions and Answers
Which amino acids have side-chain groups that can form salt bridges?
Which amino acids have side-chain groups that can form salt bridges?
- Glutamate (correct)
- Histidine (correct)
- Aspartate (correct)
- Arginine (correct)
- Lysine (correct)
What are salt bridges?
What are salt bridges?
The result of ionic bonds that form between the ionized side chain of an acidic amino acid (COOH-) and the side chain of a basic amino acid (NH3+).
What are disulfide bridges?
What are disulfide bridges?
A disulfide linkage can form between two cysteine residues that are close to each other in the same chain or between cysteine residues in different chains.
How do hydrogen bonds form in proteins?
How do hydrogen bonds form in proteins?
What are hydrophobic interactions?
What are hydrophobic interactions?
What do glycine, alanine, valine, leucine, isoleucine, phenylalanine, proline, and methionine have in common?
What do glycine, alanine, valine, leucine, isoleucine, phenylalanine, proline, and methionine have in common?
Which of the following amino acids have side chains that could participate in hydrogen bonding?
Which of the following amino acids have side chains that could participate in hydrogen bonding?
What determines the globular shape of proteins in aqueous solutions?
What determines the globular shape of proteins in aqueous solutions?
What influences the quaternary structure in proteins?
What influences the quaternary structure in proteins?
What is a subunit in the context of proteins?
What is a subunit in the context of proteins?
What is the primary structure of proteins?
What is the primary structure of proteins?
What happens when a proton is added to an amino acid?
What happens when a proton is added to an amino acid?
What happens when a proton is removed from an amino acid?
What happens when a proton is removed from an amino acid?
What is a zwitterion?
What is a zwitterion?
When pH is less than the pI for an amino acid, what is the net charge of the amino acid?
When pH is less than the pI for an amino acid, what is the net charge of the amino acid?
When pH is greater than the pI for an amino acid, what is the net charge of the amino acid?
When pH is greater than the pI for an amino acid, what is the net charge of the amino acid?
How are amino acids linked together?
How are amino acids linked together?
What describes the secondary structure of proteins?
What describes the secondary structure of proteins?
What type of bonding holds the secondary structure of a protein together?
What type of bonding holds the secondary structure of a protein together?
Which amino acid can form covalent disulfide bridges?
Which amino acid can form covalent disulfide bridges?
What type of interaction do salt bridges refer to?
What type of interaction do salt bridges refer to?
Salt bridges occur between which types of amino acids?
Salt bridges occur between which types of amino acids?
Flashcards
Salt Bridges
Salt Bridges
Ionic bonds between acidic (ionized COOH-) and basic (ionized NH3+) amino acid side chains.
Disulfide Bridges
Disulfide Bridges
Covalent linkages between two cysteine residues.
Hydrophobic Interactions
Hydrophobic Interactions
Attraction between nonpolar groups in an aqueous environment.
Nonpolar Amino Acids
Nonpolar Amino Acids
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Polar Amino Acids
Polar Amino Acids
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Quaternary Structure Stability
Quaternary Structure Stability
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Protein Subunit
Protein Subunit
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Primary Structure
Primary Structure
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Conjugate Acid
Conjugate Acid
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Conjugate Base
Conjugate Base
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Isoelectric Point (pI)
Isoelectric Point (pI)
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Amino Acid in Acidic Conditions
Amino Acid in Acidic Conditions
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Amino Acid in Basic Conditions
Amino Acid in Basic Conditions
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Zwitterion
Zwitterion
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Amino Acid Structure
Amino Acid Structure
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Secondary Structure
Secondary Structure
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Secondary Structure Stabilization
Secondary Structure Stabilization
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Cysteine's Special Ability
Cysteine's Special Ability
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Importance of Interactions
Importance of Interactions
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Protein Primary Structure
Protein Primary Structure
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Salt Bridge Definition
Salt Bridge Definition
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Nonpolar Groups Location
Nonpolar Groups Location
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Study Notes
Amino Acids and Interactions
- Aspartate, arginine, lysine, glutamate, and histidine can form salt bridges due to their charged side-chain groups.
- Salt bridges result from ionic bonds between acidic (ionized COOH-) and basic (ionized NH3+) amino acid side chains.
- Disulfide bridges are formed by covalent linkages between two cysteine residues within or between polypeptide chains.
- Hydrogen bonds can occur between side chains with amino, hydroxyl, and amide functional groups, stabilizing protein structures.
- Hydrophobic interactions arise when nonpolar groups are drawn together in an aqueous environment, common in phenylalanine residues.
Amino Acids Properties
- Glycine, alanine, valine, leucine, isoleucine, phenylalanine, proline, and methionine have nonpolar side chains.
- Glutamate, histidine, aspartate, lysine, and arginine possess side chains capable of hydrogen bonding.
- Polar groups in a protein's structure typically orient outward, while nonpolar groups direct inward to minimize water exposure.
Protein Structures
- Quaternary structure stability is influenced by hydrogen bonding, hydrophobic interactions, ionic attractions, and disulfide bridges.
- A subunit of a protein refers to a polypeptide chain with its distinct conformation that contributes to the overall protein structure.
- The primary structure of a protein remains unchanged during cooking, as it refers to the sequence of amino acids linked in a chain.
Amino Acid Ionization
- Adding a proton to an amino acid creates a conjugate acid, while removing a proton generates a conjugate base.
- In acidic conditions (pH < pI), amino acids bear a positive net charge; in basic conditions (pH > pI), they have a negative charge.
- The ionized form of amino acids exists as zwitterions, featuring both positive and negative charges balanced within the molecule.
Structural Characteristics
- Each amino acid contains an amino group (-NH2), a carboxyl group (-COOH), and a variable R group or side chain.
- Secondary structure patterns of amino acid chains, such as alpha helices and beta-pleated sheets, are stabilized by hydrogen bonding.
- Cysteine is the only amino acid that can form covalent disulfide bridges with itself, important for protein stability.
Additional Notes
- Salt bridges are specific types of ionic interactions occurring between two amino acids with ionized side chains, enhancing protein structure.
- Understanding these interactions is crucial for comprehending protein folding, stability, and function within biological systems.
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Description
Test your knowledge on proteins in this Chm 124 flashcard quiz. Explore key concepts such as salt bridges and the amino acids involved in their formation. Enhance your understanding of protein structure and interactions.
