Biochemical reactions - nitrate assimilation, Biology

Assignment Help:

Biochemical Reactions - Nitrate Assimilation

Nitrate is the most readily available and preferred source of nitrogen for growth. Assimilatory reduction of NO-3 to NH3 is known to occur in two steps as shown below:

1939_Biochemical Reactions - Nitrate Assimilation.png

The first step is catalysed by nitrate reductase (NR) which reduces NO-3 to NO-2 at the expense of two electrons. The second step is catalysed by nitrite reductase which - converts NO-2 into NH3 at the expense of six electrons. Nitrate reductase is Mo-enzyme like dinitrogenase and nitrite reductase is Fe-protein. The physiological source of reductant for the two reductive processes could be reduced ferredoxin - Fd(red) or reduced pyridine nucleotides (NADH or NADPH) depending upon the system. It is important to point out here that NO-3 is known to undergo dissimilation in which it is reduced to N2 gas. Such a process of nitrate metabolism is called nitrate respiration or denitrification and occurs exclusively in certain bacterial forms under anaerobic condition. The enzymes of denitrification of nitrate are called dissimilatory nitrate reductases.


Related Discussions:- Biochemical reactions - nitrate assimilation

Assessment of acute rheumatic fever, Assessment   While assessing the p...

Assessment   While assessing the patient with rheumatic fever, a detailed history including, problematic environmental factors or recent exposure to streptococcal infection is

Respiratory care on admission of patient, Respiratory Care on Admission (Fi...

Respiratory Care on Admission (First two hours) Patient is incubated and ventilator-dependent.  Monitor blood gases hourly and take corrective action immediately.

Man-made disasters- chemical disasters, Chemical disasters arise from harm...

Chemical disasters arise from harmful and potentially hazardous chemicals, which if released of misused can pose a threat to the environmental. Its range depends upon military and

Visualize patient ductus arteriosus, Q. Visualize Patient Ductus Arteriosus...

Q. Visualize Patient Ductus Arteriosus? Best view to visualize a patient ductus arteriosus is high parasternal or ductal view. A patient ductus arteriosus in this view is see

Gibberellins in plant growth , Gibberellins in plant growth  Gibbere...

Gibberellins in plant growth  Gibberellins were first isolated from the culture of a fungus Gibberella fujikuori. Gibberellins has a significant effect on stem elongation

Explain ventricular septal defects vsd chsude technique, Explain Ventricula...

Explain Ventricular septal defects VSD Chsude Technique ? Ventricular septal defects are closed on cardiopulmonary bypass. Approach is through median stemotomy. Ascending aort

Establish a true breeding flock of gray andalusian chickens, 1. Andalusian ...

1. Andalusian chickens may be either black, white, or gray. The gene for black is not dominant over the gene for white, nor is the gene for white dominant over the gene for black.

What are the attribute of amylase inhibitors, What are the attribute of amy...

What are the attribute of amylase inhibitors? This has been attributed to a number of reasons, Let us see how these inhibitors act. The inhibitor forms a complex with amylase,

Blood plasma - circulation, Blood Plasma - Circulation Centrifugation...

Blood Plasma - Circulation Centrifugation of blood results in its separation into two portions - a packed mass of cells which constitute around 45 per cent of the volume of t

What are the fruiting bodies present in some fungi, What are the fruiting b...

What are the fruiting bodies present in some fungi? Fruiting bodies are structures made of hyphae that project radially from the superior portion of the peduncle of some fungi.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd