Answer:
There are 4 tryptophans in the protein.
Explanation:
According to question, protein contains one tyrosine residue and say x number of tryptophans.
Concentration of protein solution = 1.0 micromolar = [tex]1.0\times 10^{-6} Molar[/tex]
Molar absorptivity of a protein solution : [tex]\epsilon [/tex]
[tex]\epsilon = \epsilon _{tyro}+\epsilon _{tryp}[/tex]
[tex]=1\times 2000 M^{-1}cm^{-1}+x\times 5500 M^{-1}cm^{-1}[/tex]
Length of the cuvette = l = 1.0 cm
Absorbance of protein solution at 280 nm = A = 0.024
[tex]A=\epsilon \times l\times c[/tex] ( Beer-Lambert's law)
[tex]0.024=(1\times 2000 M^{-1}cm^{-1}+x\times 5500 M^{-1}cm^{-1})\times 1 cm\times 1.0\times 10^{-6} M[/tex]
Solving for x :
x = 4
There are 4 tryptophans in the protein.
