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 = 
Molar absorptivity of a protein solution : 


Length of the cuvette = l = 1.0 cm
Absorbance of protein solution at 280 nm = A = 0.024
( Beer-Lambert's law)

Solving for x :
x = 4
There are 4 tryptophans in the protein.
Troposphere, this is the layer of the atmosphere closest to the earths crust.
the law of thermodyanamic is the restatement of the law of conservation of energy
Answer:
One AMU or 1 Atomic Mass Unit