1. A chromophore forms in a protein in an autocatalytic process. The protein has

Question

1. A chromophore forms in a protein in an autocatalytic process. The protein has an extinction coefficient at 280 nm of 8500 M cm and the chromophore has an extinction coefficient at 550 nm of 2200 M'cm1. You start with a protein that has an absorbance of 0.51 at 280 nm in a 1 cm cuvette. You observe an immediate increase in the absorption at 550 nm from 0 to 0.066 after you suddenly shift the pH from 10 to 4. Calculate the 1-1 a) protein concentration b) chromophore concentration c) chromophore/protein ratio

Explanation / Answer

According to the Beer's Law, A = ELC where A is the absorbance, E is the extinction coefficient, L is the path length and C is the concentration of the species.

For the protein, A = 0.51 = 8500 X 1 X Cprotein => Cprotein = 5.88 X 10 ^-5

For the chromophore, A = 0.066 = 2200 X 1 X Cchromophore => Cchromophore = 3 X 10 ^ -5

=> Cchromophore/Cprotein = 3 X 10^-5 / 5.88 X 10 ^-5 = 0.51

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.