The action potential spreads throughout the myocardium in the following sequence: SA node  Atrial internodal tracts and atria  AV node  Bundle of His  Purkinje system  Ventricles

#Id: 7708

#Unit 1. Molecules and their Interaction Relevant to Biology

                  Type l'β turn

#Id: 7709

#Unit 1. Molecules and their Interaction Relevant to Biology

                              Type II β turn

#Id: 7710

#Unit 1. Molecules and their Interaction Relevant to Biology

#Id: 7711

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                                 α-Turn

Contains hydrophilic amino acids and protrudes outside the protein surface like a hook.

Consists of 5 amino acids, generally termed as i, i+1, i+2, i+3 and i+4

H-bond is seen between i and i+4 (First and Fifth residue)

The conformation of i+1, i+2 and i+3 are crucial and on the basis of this, they are classified into

9 groups

#Id: 7712

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                γ-Turn

Consists of 3 amino acids, generally termed as i, i + 1 and i + 2

H-bond is seen between i and i + 2 (First and Third residue)

The conformation of i + 1 is crucial and on the basis of this, they are classified into 2 groups

The dihedral angles of residue i + 1 are (70, -60) and (-70, 60) of the classical and inverse gamma turns

#Id: 7713

#Unit 1. Molecules and their Interaction Relevant to Biology

                                                        𝝅-Turn

Consists of 6 amino acids, generally termed as i, i + 1 , i + 2 i + 3 i + 4 and i + 5

H-bond is seen between i and i + 5 (First and sixth residue)