BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The Ramachandran plot shows the statistical distribution of the combinations of the backbone dihedral angles and . In theory, the allowed regions of the Ramachandran plot show which values of the Phi/Psi angles are possible for an amino acid, X, in a ala-X-ala tripeptide (Ramachandran et al., 1963).

Detailed explanation-2: -By making a Ramachandran plot, protein structural scientists can determine which torsional angles are permitted and can obtain insight into the structure of peptides.

Detailed explanation-3: -Peptides that are unstructured will have all the backbone dihedral angles in the. disallowed regions.

Detailed explanation-4: -The colouring/shading on the plot represents the different regions described in Morris et al. (1992): the darkest areas (here shown in red) correspond to the “core” regions representing the most favourable combinations of phi-psi values. Ideally, one would hope to have over 90% of the residues in these “core” regions.