Question

The dihedral angles $\phi$, $\psi$ are referred to as

• A. Edman angles
• B. Ramachandran angles
• C. Pauling angles
• D. Watson angles

Hint:

$\phi$, $\psi$ = Ramachandran Plot = Protein Backbone.

Answer 1

The Correct Option is B

Step 1: Concept
Protein backbone conformation is described by the rotation around the $N—C\alpha$ and $C\alpha—C$ bonds.

Step 2: Meaning
The angle of rotation around the $N—C\alpha$ bond is $\phi$, and the angle around the $C\alpha—C$ bond is $\psi$.

Step 3: Analysis
G.N. Ramachandran used these angles to plot the sterically allowed regions for secondary structures (like $\alpha$-helices and $\beta$-sheets), resulting in the Ramachandran Plot.

Step 4: Conclusion
These dihedral angles are named Ramachandran angles. Final Answer: (B)