(5) A myoglobin similar to the example we did in class had the protonation of a
ID: 87549 • Letter: #
Question
(5) A myoglobin similar to the example we did in class had the protonation of a histidine residue coupled to the oxidation of a heme. The histidine had a pKA of 6.0 when the heme is oxidized and 7.1 when the heme is reduced. At pH 9.5, the reduction potential of the heme is +275 mV vs NHE.
(a) Draw the thermodynamic box that describes this system
(b) Predict the reduction potential at pH 3.
(c) The net charge at the iron center really cycles between 0 and +1, as the nitrogens at the center of the porphyrin ring have a total net charge of -2. Assuming a dielectric constant of 6, predict the distance between the heme iron and the histidine side chain.
Explanation / Answer
5a)The concept of an open system was formalized with in a frame work that enabled one to interrelated the theory of the organ , thermodynamics and envoivutionary theory.In the natural science an open system is one whose border is permeable to both energy and mass.In thermodynamics a closed system by contrast is permeable to energy but not the to matter.Open system have a no of consequences.A closed system contains limited energies.The difference of an open system assumes that there are supplies.
B)It is easy to explain with specific example for predicted at pH 6
What could you use to oxidized iron (2) ions to iron (3) ions ?
The E°value for this reaction is to change iron (2)ions into iron (3)ions you need to persuade this equilibrium this iron E°value must be more negative lEss positive one.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.