Question

Understand why formation of α-helices and β-sheets is energetically favorable. Just need background info/summary.

Answer 1

two adjacent amino acid residues are hydrogen bonded.

it is necessary to orient 6 torsional angles for formation of a single turn of alpha helix which results in formation of single hydrogen bond. addition of more turns reuire introduction of 3 hydrogen bonds . process of adding turns to nucleation site refers to the cooperative effect in producing alpha helix.

ΔG=ΔH−TΔS if the ΔG is negative then reaction is spontaneous .A higher entropy is constantly good unless a more prominent negative enthalpy esteem can make up for the reduction in entropy. enthalpy can be aquired by hydrogen bonding , vander wal interactions alpha helices lie in region from phi= -60 degree to -120 degree and psi = -60 degree .

in Beta sheets beta strands are connented by 2 or 3 hydrogen bonds which leads to formation of twisted pleated sheets. beta sheets involve long distance interactions.