Lecture 2 Quiz

What is the correct order of protein structures from simplest to most complex?

• Primary structure, Secondary structure, Tertiary structure, Quaternary structure
• Quaternary structure, Tertiary structure, Secondary structure, Primary structure
• Primary structure, Tertiary structure, Secondary structure, Quaternary structure
• Secondary structure, Primary structure, Tertiary structure, Quaternary structure

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