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

Biocontrol agents , Use of micro-organisms to control insect pests, pathog...

Use of micro-organisms to control insect pests, pathogens or weeds constitutes biological control, and the biological agents employed are called biocontrol agents. Micro-organis

Define radiological anatomy, Q. Define Radiological anatomy? The border...

Q. Define Radiological anatomy? The borders of the mediastinum on the CXR are defined by the contrast produced by adjacent air filled lung. Postero-Anterior View It in

Proteins of animal origin - fish, Proteins of Animal Origin - Fish Fish...

Proteins of Animal Origin - Fish Fish: The edible portion is skeletal muscles of the body. Even though the skeletal muscles of different animals are basically similar, fish spe

Explanation of glomerular filtration, Question 1) Mentioning the 3 diff...

Question 1) Mentioning the 3 different processes in the formation of urine Explanation of Glomerular filtration Explanation of Tubular reabsorption Explanation of T

Diseases related with kidney, DISEASE CONCERNED WITH KIDNEY - 1.      P...

DISEASE CONCERNED WITH KIDNEY - 1.      Paget's disease - Abnormalities of kidney. 2.      Uramia - Increases in quantity of urea. 3.      Nephritis - Inflamation in glom

Explain dna binding domains, Helix-turn-helix This  motif  have  of  tw...

Helix-turn-helix This  motif  have  of  two    -helices  divided  by  a  short  (four-amino   acid) peptide  sequence  which  forms  a   -turn that shown in above figure.  When

How are the transparency and functions of cornea evaluated, How are the tra...

How are the transparency and functions of cornea evaluated? Physiological roles of barrier function, refractive function (with interaction of tear film), response to wound and

Criteria for implant success as given by albrektsson, Q. Show the Criteria ...

Q. Show the Criteria for Implant Success as given by Albrektsson? Criteria for Implant Success as given by Albrektsson are: 1. An individual unattached implant is immobile w

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