Biochem: Protein Secondary Structure

Flashcards covering key concepts from the lecture on protein secondary structures, including types of structures, their characteristics, and the importance of dihedral angles.

What are the two common secondary structures defined in protein segments?

α helix and β conformation.

What do φ and ψ angles represent in protein secondary structure?

They define the conformation and spatial arrangement of the polypeptide chain.

What is a Ramachandran plot used for?

To visualize φ and ψ values for protein structures.

What is the characteristic arrangement of an α helix?

The backbone is wound around an imaginary longitudinal axis with R groups protruding outward.

How many residues per turn are there in an α helix?

3.6 residues.

What type of bonding contributes to the stability of the α helix?

Intrahelical hydrogen bonds.

Which amino acids are known to occur infrequently in an α helix?

Proline and Glycine.

What orientation do antiparallel β sheets have compared to parallel β sheets?

Antiparallel β sheets have opposite orientations while parallel β sheets have the same orientation.

What do β turns connect in a protein structure?

They connect the ends of two adjacent segments of an antiparallel β sheet.

What is a key feature of the dihedral angles associated with common secondary structures?

Each secondary structure has characteristic φ and ψ angles.