Question

Why the different secondary structures of protein absorbs light differently?

Answer 1

Answer:

Absorption of light by protein molecules are used for analysis of the secondary structure of proteins.

Secondary structures exist in many forms like

• Alpha Helix
• Beta pleated sheat
• Motiffs (Super 2° structures)

Now ,

In these of structures, when light is absorbed, the electrons are elevated or excited to higher orbits.

They always absorb a wavelength range between 180 - 230 nm.

Molecular orbital theory helps us to understand re-hybridisation of lone pair of electrons of Nitrogen.

Such changes causes differences in absorption Spectra of the protein secondary structures.

Answer 2

Answer:

$The peptide bonds in aprotein's asymmetric environment will absorbthis range of light(promoting electrons to higher energy levels). In different secondary structures , the peptide bond electrons will absorb right and left circularly polarized light differently(for example, they have different molar absorptivities).$