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

Cardio pulmonary bypass , CARDIO PULMONARY BYPASS  :  Open-heart surgery i...

CARDIO PULMONARY BYPASS  :  Open-heart surgery is considered as one of the most significant advances in medicine of 20th century. Establishment of safe cardio pulmonary bypass (CP

Fourth week to eight week - embryonic development, Fourth Week to Eight Wee...

Fourth Week to Eight Week - Embryonic Development The common changes in body shape and plan of the embryo from fourth week to eighth week are displayed in Figure. The fourth

Canned and retort pouched meat products, C a nned and Retort Pouched Meat...

C a nned and Retort Pouched Meat Products Canning as a process contributes to preservation, storage and distribution of food supplies. Production of thermally processed meat

What is phylum platyhelminthes - flatworms, What is Phylum Platyhelminthes ...

What is Phylum Platyhelminthes - Flatworms ? This Class consists of the free-living flatworms, the best known of which is the Genus Planaria. Most of the species in this class

Define the factors that affect the rate of drying, Define the Factors that ...

Define the Factors that Affect the Rate of Drying? Factors that affect the rate of drying are as follow: 1) The fat content of the food-Higher fat contents generally result

Define preoperative care prior to endodontic microsurgery, Define Preoperat...

Define Preoperative Care Prior to Endodontic Microsurgery a.Thorough medical history "consultation and permission from the physician is the patient has systemic disease(s) and

Which harmone is not associated with male reproduction, Which of the below ...

Which of the below is NOT hormone associated with male reproductive physiology: a) Prolactin b) Testosterone c) Interstitial hormone d) Follicle-stimulating hormone

Difference between lamarckism and neo-lamarckism, DIFFERENC E BETWEEN LAMA...

DIFFERENC E BETWEEN LAMARCKISM AND NEO-LAMARCKISM - S.No Lamarckism Neo-Lamarckism 1. It refers of the original

What would be the progeny of these crosses, Suppose that you are raising Do...

Suppose that you are raising Downton wombats, carefully because they bite when teased.You notice that some of your wombats have white spots, whereas others have solid coats. What t

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