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

What is the mechanism of elisa, ELIZA stands for enzyme linked immune diffu...

ELIZA stands for enzyme linked immune diffusion assays. It works on standard of antigen antibody reaction.

Enteric infectious viral disease, Match each item in Column A with the corr...

Match each item in Column A with the corresponding item in Column B regarding infectious diseases Column A Column B a. Pulmonary tuberculosis i. Enteric infectious protozoan diseas

Explain what is prosthetic valve endocarditis, Explain what is Prosthetic V...

Explain what is Prosthetic Valve Endocarditis (PVE) ? Prosthetic valve endocarditis (PVE) is called EARLY when symptoms begin within 60 days of surgery and LATE when the onset

Determine the principles of suturing, Determine the Principles of suturing ...

Determine the Principles of suturing These are universal principles which are applicable in all aspects not just implant surgery: 1. Sutures should always be inserted throug

Bovine spongiform encephalopathy (bse), B o vi n e spongiform encephalo...

B o vi n e spongiform encephalopathy (BSE) Bovine spongiform encephalopathy (BSE) is a transmissible, neurodegenerative, fatal brain disease of cattle characterized by post

Lab safety, Why should you not apply cosmetics while doing a lab experiment...

Why should you not apply cosmetics while doing a lab experiment in class?

Agro-industrial by-products-non-conventional feed resources, Non-Convention...

Non-Conventional Feed Resources There are many non-traditional or non-conventional materials which are available in abundance and can form potential source of feedstuffs for f

How age affects the bmr, How Age affects the BMR? The BMR per unit weig...

How Age affects the BMR? The BMR per unit weight also varies with age, being higher in children and lower in the elderly. The loss of FFM with ageing is associated with a decli

Abolition of arrhythmias by exercise, Q. Abolition of Arrhythmias by Exerci...

Q. Abolition of Arrhythmias by Exercise? The induction of arrhythmias by exercise is well recognized, but the abolition of ectopic activity is less commonly appreciated. The me

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