There are 3 cellular ways to treat mutations on DNA

Repair- Most common

Reversal- Most expensive and rare

Bypass – Last resort and carry mutation without correction

TLS Online TPP Program

#Id: 4718

#Unit 13. Methods in Biology

Electron delocalisation extends throughout the cyclic tetrapyrrole ring of porphyrins and gives rise to an intense transition at 400 nm called the Soret band.

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.