Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Nitrogen Cycle01:49

The Nitrogen Cycle

54.3K
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
54.3K
Overview of Nitrogen Metabolism01:20

Overview of Nitrogen Metabolism

8.5K
Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of  ammonia, ammonium ions, nitrate, nitrite, or  nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this...
8.5K
Inorganic Nitrogen Assimilation01:22

Inorganic Nitrogen Assimilation

108
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
108
Metabolism of Chemolithotrophs01:15

Metabolism of Chemolithotrophs

176
Chemolithotrophs are microorganisms that obtain energy by oxidizing inorganic molecules such as hydrogen gas (H₂), ammonia (NH₃), reduced sulfur compounds (H₂S, S²⁻), and ferrous iron (Fe²⁺). Unlike heterotrophic organisms that rely on organic carbon, chemolithotrophs transfer electrons from these inorganic donors to the electron transport chain (ETC), generating a proton motive force (PMF) that drives ATP synthesis through oxidative phosphorylation.
176
2° Amines to N-Nitrosamines: Reaction with NaNO201:20

2° Amines to N-Nitrosamines: Reaction with NaNO2

4.6K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.6K
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview01:26

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview

3.5K
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
3.5K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Toxicity vs. Detoxification of Sulfite, Nitrite, and Arsenite by Metalloenzymes: Implications for Health and Environment.

Chemistry (Weinheim an der Bergstrasse, Germany)·2026
Same author

Magnetic interactions between metal sites in complex enzymes.

Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry·2025
Same author

Correction: Factors influencing the high performance of IT staff.

Scientific reports·2025
Same author

Factors influencing the high performance of IT staff.

Scientific reports·2025
Same author

Revisiting the metal sites of nitrous oxide reductase in a low-dose structure from Marinobacter nauticus.

Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry·2024
Same author

Selenium-More than Just a Fortuitous Sulfur Substitute in Redox Biology.

Molecules (Basel, Switzerland)·2024
Same journal

Correction: Chen et al. Chemical Composition of <i>Litsea pungens</i> Essential Oil and Its Potential Antioxidant and Antimicrobial Activities. <i>Molecules</i> 2023, <i>28</i>, 6835.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Ruan et al. Comparison of Extraction, Isolation, Purification, Structural Characterization and Immunomodulatory Activity of Polysaccharides from Two Species of <i>Cistanche</i>. <i>Molecules</i> 2025, <i>30</i>, 4754.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Li et al. Gastrodin Ameliorates Cognitive Dysfunction in Vascular Dementia Rats by Suppressing Ferroptosis via the Regulation of the Nrf2/Keap1-GPx4 Signaling Pathway. <i>Molecules</i> 2022, <i>27</i>, 6311.

Molecules (Basel, Switzerland)·2026
Same journal

Correction: Zueva et al. Steady-State Kinetics of Enzyme-Catalyzed Hydrolysis of Echothiophate, a P-S Bonded Organophosphorus as Monitored by Spectrofluorimetry. <i>Molecules</i> 2020, <i>25</i>, 1371.

Molecules (Basel, Switzerland)·2026
Same journal

1,4-Diazatriphenylene and Its Hetero-Fused Analogs: Synthesis and Applications.

Molecules (Basel, Switzerland)·2026
Same journal

Comparative Phytochemical Studies on the Aerial Parts of <i>Teucrium davaeanum</i> Coss. and <i>Teucrium zanonii</i> Pamp.

Molecules (Basel, Switzerland)·2026
See all related articles

Related Experiment Video

Updated: Sep 13, 2025

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
08:05

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Published on: October 7, 2020

6.2K

Nitrate-Nitrite Interplay in the Nitrogen Biocycle.

Biplab K Maiti1, Isabel Moura2, José J G Moura2

  • 1Department of Chemistry, School of Sciences, Cluster University of Jammu, Jammu 180001, India.

Molecules (Basel, Switzerland)
|July 30, 2025
PubMed
Summary
This summary is machine-generated.

Nitrate reductases and nitrite oxidoreductases, key to the nitrogen cycle, share surprising similarities. This review explores their structure, function, and evolutionary links, revealing a unified mechanism in microbial nitrogen metabolism.

Keywords:
mo-dependent enzymesnitrate reductasenitrite oxidoreductasenitrogen-biocycle

More Related Videos

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
07:59

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Published on: December 6, 2018

8.3K
The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
10:11

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Published on: August 3, 2016

10.0K

Related Experiment Videos

Last Updated: Sep 13, 2025

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
08:05

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O

Published on: October 7, 2020

6.2K
Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
07:59

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Published on: December 6, 2018

8.3K
The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations
10:11

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Published on: August 3, 2016

10.0K

Area of Science:

  • Biogeochemistry
  • Microbial Metabolism
  • Enzymology

Background:

  • The nitrogen cycle (N-cycle) is crucial for global biogeochemistry, influencing atmospheric chemistry, agriculture, and ecosystems.
  • Nitrate (NO3-) and nitrite (NO2-) interconversion, mediated by Nitrate Reductases (NARs) and Nitrite Oxidoreductases (NXRs), is central to the N-cycle.
  • NARs and NXRs, despite catalyzing opposing reactions, display significant structural and mechanistic parallels.

Purpose of the Study:

  • To elucidate the molecular mechanisms of nitrate reduction and nitrite oxidation.
  • To explore the structural, mechanistic, and evolutionary relationships between NARs and NXRs.
  • To highlight oxygen atom transfer (OAT) as a unifying principle and discuss bidirectional catalytic potential.

Main Methods:

  • Review of recent structural, spectroscopic, and thermodynamic data.
  • Analysis of enzymatic architectures and redox mechanisms.
  • Examination of evolutionary relationships.

Main Results:

  • NARs and NXRs exhibit remarkable structural and mechanistic similarities, functioning as "two sides of the same coin" in nitrogen metabolism.
  • Oxygen atom transfer (OAT) serves as a unifying mechanistic principle for both enzyme families.
  • Environmental redox conditions and bidirectional catalytic potential influence enzyme function.

Conclusions:

  • Understanding the interconversion between nitrate and nitrite provides insights into the flexibility of nitrogen-transforming pathways.
  • This knowledge has implications for environmental management, biotechnology, and synthetic biology.
  • The study emphasizes the interconnectedness of nitrogen metabolism through shared enzymatic mechanisms.