The nucleosome has an approximate twofold axis of symmetry, called the dyad axis.

TLS Online TPP Program

#Id: 4721

#Unit 13. Methods in Biology

The absorption spectra of the bases in polymers are sensitive to pH and greatly influenced by electronic interactions between bases.

TLS Online TPP Program

#Id: 4722

#Unit 13. Methods in Biology

Biochemical samples are usually buffered aqueous solutions, which has two major advantages. Firstly, proteins and peptides are comfortable in water as a solvent, which is also the ‘native’ solvent. Secondly, in the wavelength interval of UV/Vis (700–200 nm) the water spectrum does not show any absorption bands and thus acts as a silent component of the sample

TLS Online TPP Program

#Id: 4723

#Unit 13. Methods in Biology

The absorption spectrum of a chromophore is only partly determined by its chemical structure. The environment also affects the observed spectrum, which mainly can

be described by three parameters:

protonation/deprotonation (pH, RedOx);

• solvent polarity (dielectric constant of the solvent); and

• orientation effects.

TLS Online TPP Program

#Id: 4724

#Unit 13. Methods in Biology

Concentration of protein can be analyzed by to method constructive and destructive method 

TLS Online TPP Program

#Id: 4725

#Unit 13. Methods in Biology

Destructive method uses Folin reagent, Biuret, BCA, Coomassie Brilliant Blue and give absorbance at 660, 540, 562, 595 nm of wavelength respectively.

TLS Online TPP Program

#Id: 4726

#Unit 13. Methods in Biology

The constructive method involved direct analysis of protein and gives absorbance at wavelength of 280 nm.