Question

1. [04] At the end of nitrogen fixation, the following reaction occurs: N2 + 8 + 2 Nike + H2 a. What product belongs in the blank? b. How many electrons (e s) are involved in the above reaction and where do they come from? c. What does “Mo" have to do with nitrogen fixation? d. For each nitrogen atom "fixed", 13 APTs are required? Show how is that number of ATPs calculated? 2. [04] The synthesis of the urea cycle intermediate ornithine from glutamate is glutamate + NH3 + 2NADPH + ATP ornithine + 2NADP + H2O + ADP + P Using the non-ionic forms of the carboxylic acids, amino groups, and ammonia, suggest an appropriate, detailed pathway no mechanisms required, just intermediate structures and co-enzymes. The amino group is incorporated by reductive amination not transamination. НО. glutamate (gu)

Answer 1

Notes Date Notes @ Date N + 8H+ + Bé - 2 Niy til 6 8 electrons are involved. The electrons required for reduction of N are transfered to nitrogen' by reduced form of femrodoxins and flavodo kins. - The source of elecoon is oxidation of Pyruvate © Mo presence is necessary as the co-ordination of N occurs at the Mo site of the enzyme. 5 Fe ZE Fers - Mo. Enzyme Active site of Mo-Fe Botein (Nitrogenase.) + 16 Mg ATP +84 +86 → 2 H Hz 16 Mg ADP + 16 Pit hy CamScanner

The reaction requires 16 molecules of ATP plus the enzyme Nitrogenase.Nitrogenase consists of two proteins Fe protein and Mo protein.The reaction occurs when nitrogen binds to enzyme complex coordinated at the Mo center.