Sandbox Reserved 760: Difference between revisions
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If flux of the Fe-protein is high, E2H2 will again be reduced and protonated, leading to E3H3, which again can produce H2. Dinitrogen then binds only when there are up to 3 or 4 electrons supplied.The binding of dinitrogen produces one H2 and leads to E3HN2. In its turn, H2 can act as an inhibitor to N2. The state E3H3 may be reduced to E4H4 which then can bind N2 along with H2 production. The protein goes back to its oxidized state if no more substrate is available to be reduced and N2 is protonated until NH3 is released. Since the FeMo-protein undergoes its major changes at the binding | If flux of the Fe-protein is high, E2H2 will again be reduced and protonated, leading to E3H3, which again can produce H2. Dinitrogen then binds only when there are up to 3 or 4 electrons supplied.The binding of dinitrogen produces one H2 and leads to E3HN2. In its turn, H2 can act as an inhibitor to N2. The state E3H3 may be reduced to E4H4 which then can bind N2 along with H2 production. The protein goes back to its oxidized state if no more substrate is available to be reduced and N2 is protonated until NH3 is released. Since the FeMo-protein undergoes its major changes at the binding | ||
region of the Fe-protein during complex formation, it is understood that the substrates enter and leave protein through the homocitrate – P-cluster pathway. | region of the Fe-protein during complex formation, it is understood that the substrates enter and leave protein through the homocitrate – P-cluster pathway. | ||
Reactions with the nitrogenase system include the following; | |||
2H+ + 2e- →H2 | |||
N2 + 8H+ + 8e- →2NH3 + H2 | |||
N2 O + 2H+ + 2e- + N2 + H 2O | |||
CN- + 7H+ + 6e- →CH4 + NH3 | |||
CH 3NC + 6+ + 6e- →CH 3NH2 + CH4 | |||
N3- + 3H+ + 2e- → N2 + NH3 | |||
C 2H2 + 2H+ + 2e- →C 2H 2 | |||
CH 2CHCH +2H+ + 2e- →CH2CH2CH2 | |||
H2N-CN + 6H+ + 6e- → NH3 + CH3NH2 | |||
CH2 N=N + 6H' + 6e- → CH3NH2 + NH3 | |||
All substrates in the reactions above compete for electrons from the same pool of reduced dinitrogenase, as they inhibit each other. Among the substrates listed, only N2O is a competitive inhibitor of N2 reduction, and the others are noncompetitive inhibitors. Other inhibitors include CO, H2 , CS2. | |||
== '''APPLICATION OF DEHYDROGINASE''' == | |||
Nitrogen is abundant and makes up about 70% of the atmosphere. It is required by plants as fertilizer (nutrient), but they | |||
can not readily access it because dinitrogen as we have discussed earlier is bound by one of the strongest covalent bonds in nature (triple bond). Industries use the Haber-Bosch process, a method developed by Fritz Haber and Carl Bosch to break this bond and convert | |||
dinitrogen to ammonia, requiring about 500 and 450 bar. Around 80·109 kg of ammonia are manufactured every year through this process. Nature, on the other hand converts dinitrogen to ammonia in anerobic environments and low temperature conditions through the use of nitrogenase. | |||
Biological nitrogen fixation produces two or three times more ammonia per year than the industrial process. | |||
