Spectroscopy WS 1+2 W7

Question 1

In a solution, the dye has an absorption maximum of 285nm. In what region of the EM spectrum is this wavelength?

Answer 1

UV

Question 2

UV absorption causes…

Answer 2

Electrons to jump to higher energy levels

Question 3

What electronic transition requires the most energy to occur following UV absorption?

Answer 3

O-O*

Question 4

The fluorescence of Ethereum bromide is rapidly quenched by water molecules. In the presence of DNA it slides between the base pairs and act as an intercalator. When bound the fluorescence is long lived and the dye is often used for detection of DNA. Suggest why DNA binding increases the fluorescence lifetime.

Answer 4

Intercalation puts ethidium bromide into a hydrophobic environment with the base pairs in DNA so it is shielded from water

Question 5

What molecular transition will generate IR absorption?

Answer 5

A rotational transition with a wave number of 20 cm-1