14 Questions
Which type of secondary structure is stabilized by hydrogen bonds between carbonyl groups and NH groups on adjacent strands?
β sheets
Which amino acids have high tendencies to form an α-helix?
Ala, Leu, Lys, Met, uncharged Glu
In which type of secondary structure do neighboring side chains occupy opposite faces of the structure?
β sheets
Which type of secondary structure is not frequently found in proteins?
310-helix
What is the distance between residues in the α-keratin α-helix?
3.6 residues
Which fibrous protein is mostly made up of β sheets?
β-Keratin
What defines the interface between two long helices in the coiled-coil structure typical of α-keratin?
Hydrophobic side
How many residues per turn does the α-helix have?
3.6 residues
Which type of amino acid is Alanine?
Non-polar
What type of conformation does Valine prefer?
Sheet
What is the meaning of 'amphiphilic' in the context of α‐helix and β‐strand?
Having both hydrophilic and hydrophobic properties
Why is the prediction of tertiary structure difficult?
Difficulty in predicting interactions between residues that are far apart
What is the primary reason for using a combination of approaches in protein amino acid sequence analysis?
To accurately identify posttranslational modifications
What is the initial form of insulin synthesis?
Preproinsulin
Study Notes
Secondary Structure
- β-sheet is stabilized by hydrogen bonds between carbonyl groups and NH groups on adjacent strands.
Amino Acids and Helices
- Amino acids with high tendencies to form an α-helix include alanine.
- Valine prefers a β-strand conformation.
Alpha-Keratin
- α-Keratin is a type of fibrous protein made up mostly of β sheets.
- The distance between residues in the α-keratin α-helix is 0.15 nm.
- The interface between two long helices in the coiled-coil structure of α-keratin is defined by ionic interactions between glutamic and lysine residues.
Structure Characteristics
- The α-helix has 3.6 residues per turn.
- α-Helix and β-strand are amphiphilic, meaning they have both hydrophilic and hydrophobic regions.
Protein Structure Analysis
- The prediction of tertiary structure is difficult due to the large number of possible conformations.
- A combination of approaches is used in protein amino acid sequence analysis to overcome the limitations of individual methods.
Insulin Synthesis
- The initial form of insulin synthesis is preproinsulin.
Test your knowledge of protein structure with this quiz covering topics like alpha-helix, beta-sheets, and the characteristics of amino acids. Identify the backbone components and R-groups, as well as the interactions between different regions and macromolecules.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
