NEW
Font size
WorksheetsLecture 2 Quiz
Total questions: 20
Worksheet time: 20mins
What is the correct order of protein structures from simplest to most complex?
What is the main difference between Type I and Type II turns in protein structures?
Dihedral angles of central residues
Number of amino acids involved
Presence of hydrogen bonds
Involvement of glycine residues
What is the distinguishing feature of an amphipathic α helix?
Extended conformation
Distinct hydrophobic and hydrophilic faces
Presence of proline residues
Tight coiling around an axis
What is the purpose of loop regions in protein structures?
Stabilize the protein core
Provide flexibility to the structure
Form hydrogen bonds with polar groups
Connect alpha helices and beta strands
What is the function of the calcium-binding EF-hand motif?
Enhance enzymatic activity
Facilitate protein folding
Bind calcium ions
Promote protein-protein interactions
What is the structural arrangement of the Greek key motif?
Helix-turn-helix motif for DNA binding
Coiled-coil structure with repeating distance
Parallel β strands connected by an α helix
Antiparallel β sheet with specific strand arrangement
What is the characteristic of coiled-coil structures?
Form superhelix with repeating distance
Involve long dimeric coiled coils
Found in proteins that make up muscle fiber
Facilitate protein dimerization
What is the purpose of β-α-β motifs in protein structures?
Connect parallel β strands with an α helix
Promote ligand binding
Facilitate protein-protein interactions
Enhance structural stability
What is the structure of the DNA binding domains of the transcription factors Fos and Jun?
A repeating helical structure known as the armadillo motif
A closed β barrel
A four-helix bundle protein
Two α helices that coil around each other
What is the pattern of amino acids in a parallel coiled coil?
c, b, a, g, f, e, d
g, f, e, d, c, b, a
a, b, c, d, e, f, g
d, e, f, g, a, b, c
What can stabilize coiled-coil structures?
Van der Waals contacts
Hydrogen bonds
Disulfide bonds
Ionic interactions
What is the structure of bacteriorhodopsin?
Seven transmembrane helices
A porin with 16 β strands forming a barrel
A closed β barrel
A repeating helical structure known as the armadillo motif
What is the function of porins?
Bind to DNA
Form transmembrane channels
Act as enzymes
Transport metabolites
What is the role of charged residues in bacteriorhodopsin?
Stabilize the protein structure
Act as cofactors
Line a proton conducting conduit
Form hydrogen bonds with lipids
How are transmembrane α helices stabilized in membrane proteins?
Van der Waals contacts and hydrogen bonds
Disulfide bonds
Ionic interactions
Hydrophobic interactions
How many residues are approximately required for an α helix to span a lipid bilayer?
25-30
60-65
What method is commonly used to predict transmembrane α-helices from amino acid sequences?
In the context of protein structure, what does the term "amphipathic" specifically refer to?
What feature of α-helices allows them to satisfy hydrogen bonding requirements within the lipid bilayer?
Their amphipathic nature
The internal hydrogen bonding between backbone NH and C=O groups
How are binding sites in proteins typically located in relation to their structure?
