Thrombin is a serine protease that is formed from its circulating precursor, prothrombin, by the action of activated factor X.

TLS Online TPP Program

#Id: 4719

#Unit 13. Methods in Biology

Molecules such as FAD (flavin adenine dinucleotide), NADH and NADþ are important coenzymes of proteins involved in electron transfer reactions (RedOx reactions). They can be conveniently assayed by using their UV/Vis absorption: 438 nm (FAD), 340 nm (NADH) and 260 nm (NADþ).

TLS Online TPP Program

#Id: 4720

#Unit 13. Methods in Biology

The absorption of UV light by nucleic acids arises from n!p* and p!p* transitions of the purine (adenine, guanine) and pyrimidine (cytosine, thymine, uracil) bases that occur between 260 nm and 275 nm. 

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