The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

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#Id: 9267

#XL - S Microbiology

Diazotrophs are able to catalyze the enzymatic reduction of this compound to ammonia (NH3) using the enzyme nitrogenase

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#Id: 9268

#XL - S Microbiology

Nitrogenase is a complex consisting of the MoFe protein (dinitrogenase or component I) a heterotetramer, and the Fe protein (dinitrogenase reductase or component II) a homodimer.

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#Id: 9269

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Fe protein 

contains 2 identical subunits (dimer) – nif H

Each subunit has MW of 30 ~ 72 kD.

Each subunit contains an Fe-S cluster (4Fe and 4S2-).

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MoFe protein 

2 pairs of identical subunits (tetramer, nif D & nif K)

A total of MW 180 ~ 235kD

Each subunit has 2 Mo-Fe-S clusters.

Both Fe proteins and MoFe proteins are sensitive to O2. 

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#Id: 9271

#XL - S Microbiology

TLS Online TPP Program

#Id: 9272

#XL - S Microbiology