Name: nitrogen in soil and living things
Uploaded: 2019-03-11T09:21:40.000Z
Duration: 1 min 49 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

NC K-12 Science Standard Course of Study

9-12

Biology

ecosystems-interactions-energy-and-dynamics

Ecosystems- Interactions, Energy, and Dynamics

LS.Bio.4.1

The Nitrogen Cycle

- Le cycle de l'azoteimplique le mouvement des atomes d'azoteentre les éléments biotiques et abiotiques de l'écosystème. 
La plupart de l'azote de l'écosystèmeest stocké dans l'atmosphère sous la forme d'un gaz, le N2. 
Mais seules les bactéries possèdent l'enzyme requispour convertir l'azote gazeux, ou diazote,en une forme utilisable par les autres organismes :c'est la fixation du diazote. 
L'azote est donc un nutriment très limité dans l'écosystème. 
Une fois l'azote converti en ammoniacpar les bactéries du sol,les plantes peuvent convertir l'azote en protéines,ADN et autres molécules organiques,qui sont consommées par les herbivoreset décomposées en acides aminés. 
Ceux-ci peuvent être réassemblés pour former des protéinesutilisées pour la croissance et le développement,et pour l'alimentation de ceux qui les mangent. 
En même temps, les herbivores et leurs prédateursrenvoient de l'azote dans le sol sous forme de déchets. 
Les organismes morts et les déchets contiennent de l'azotesous la forme de protéine, d'urée, et d'acide urique. 
Les décomposeurs, comme les bactéries et les champignons,peuvent décomposer ces moléculesen relâchant de l'ammoniac dans le sol. 
Celui-ci peut ensuite être absorbé par les plantes,ou converti en nitrates par les bactéries nitrifiantes. 
Ces nitrates peuvent aussi être absorbées par les plantesou, en absence d'oxygène, être converties en azote gazeuxpar les bactéries dénitrifiantes. 
Les humains envoient aussi de l'azote dans l'écosystèmepar le biais d'engrais agricoles. 
Mais utilisé au mauvais moment ou en grandes quantités,l'azote en excès peut entrer dans les écosystèmes aquatiqueset augmenter la croissance des bactéries, des algueset des plantes aquatiques : c'est l'eutrophisation.

Ramakrishnan VV, Ghaly AE. « Sources d’azote et cycle dans l’écosystème et son rôle dans la pollution de l’air, de l’eau et du sol : une revue critique. » Journal of Pollution Effects & Control 03, no. 02 (2015). [<a href="https://doi.org/10.4172/2375-4397.1000136 » target="__blank">Source</a>]

le cycle de l'azote

Les atomes d’azote, présents dans toutes les protéines et l’ADN, sont recyclés entre les constituants abiotiques et biotiques de l’écosystème. Cependant, la principale forme d’azote sur Terre est l’azote gazeux, qui ne peut pas être utilisé par la plupart des animaux et des plantes. Ainsi, l’azote gazeux doit d’abord être converti en une forme utilisable par des bactéries fixatrices d’azote avant qu’il puisse traverser d’autres organismes vivants. L’utilisation d’engrais contenant de l’azote et de déchets animaux dans l’agriculture humaine a grandement influencé le cycle naturel de l’azote. 
 
 <h4>Cycle biologique de l’azote</h4>
 
 Environ 78 % de l’air que nous respirons est de l’azote gazeux. Cependant, sous cette forme, N2, peu d’organismes sont capables de l’utiliser. L’azote constitue des molécules essentielles dans tous les organismes, comme les protéines et l’ADN. Incapables d’utiliser la forme atmosphérique de l’azote, la plupart des organismes utilisent les sous-produits des procaryotes fixant l’azote et le nitrifiant. La fixation de l’azote convertit l’azote gazeux (N2) en ammoniac (NH3), tandis que la nitrification convertit NH3 en nitrites (NO2-) et en nitrates (NO3-). Les plantes peuvent utiliser directement l’ammoniac et les nitrates, et les organismes qui mangent des plantes obtiennent de l’azote en ingérant des plantes. Lorsque ces organismes meurent, les bactéries dans le sol sont capables de convertir l’azote organique en ammoniac au cours d’un processus appelé ammonification. Grâce à la dénitrification, les bactéries aérobies peuvent alors transformer l’ammoniac en azote gazeux qui est libéré dans l’atmosphère, complétant le cycle. 
 
 <h4>Puits d’azote</h4>
 
 Le principal réservoir de stockage à long terme de l’azote est l’azote gazeux dans l’atmosphère. Cependant, il y a d’autres puits d’azote plus petits dans l’écosystème. L’azote peut être retenu pendant des périodes relativement longues dans les marais, les sédiments marins et les roches sédimentaires. Cependant, comme les composés azotés sont très solubles dans l’eau, l’érosion de roches sédimentaires peut libérer de l’azote dans l’écosystème.
 
 <h4>Impacts humains sur le cycle de l’azote</h4>
 
 Comme l’azote est souvent un facteur limitant pour la croissance des plantes dans les milieux naturels, les agriculteurs ajoutent de l’azote dans le sol comme engrais pour augmenter le rendement agricole. Le ruissellement agricole dans les écosystèmes aquatiques peut entraîner une eutrophisation et une croissance anormalement rapide d’espèces toxiques d’algues. L’élevage d’une grande proportion de bétail peut également augmenter la quantité de déchets nitriques dans le sol et dans les sources d’eau locales.

Le cycle de l'azote

Les atomes d’azote, présents dans toutes les protéines et l’ADN, sont recyclés entre les composants abiotiques et biotiques de l’écosystème. Cependant, la forme primaire de ...

Education

Enseignement

JoVE Core

Biologie

Ecology

Écologie

Ecosystems

Écosystèmes

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

nitrogen in soil and living things

Nitrogen in soil and living things moves through ecosystems in several forms. Nitrogen atoms are found in proteins and DNA. Most animals and plants cannot use nitrogen gas, which is the main form of nitrogen on Earth. Nitrogen must first be changed into a usable form by nitrogen-fixing bacteria before it can move through food webs.

About 78% of the air we breathe is nitrogen gas, but few organisms can use it in that form. Nitrogen fixation changes nitrogen gas (N2) into ammonia (NH3). Nitrification then changes ammonia into nitrites (NO2-) and nitrates (NO3-). Plants can use ammonia and nitrates directly. Plant-eating organisms get nitrogen by eating plants.

When organisms die, soil bacteria break down organic nitrogen and convert it into ammonia. This process is called ammonification. Aerobic bacteria can then carry out denitrification and convert ammonia into nitrogen gas that returns to the atmosphere. That return of nitrogen gas completes the cycle.

The main long-term reservoir for nitrogen is nitrogen gas in the atmosphere. Smaller nitrogen sinks also store nitrogen for long periods. These include swamps, marine sediments, and sedimentary rock. Because nitrogen compounds dissolve easily in water, weathering of sedimentary rock can release nitrogen back into the ecosystem.

Human activity can change the nitrogen cycle. Farmers add nitrogen to soil as fertilizer because nitrogen is often a limiting factor for plant growth in natural environments. This can increase agricultural yield. However, runoff from farms can enter aquatic ecosystems and cause eutrophication, which leads to unnaturally rapid growth of toxic algae species. Large numbers of livestock can also increase the amount of nitric waste in soil and local water sources.

Nitrogen in Soil and Living Things

what is an ecosystem?

Ecosystem Zones and Climate

Ecosystems are shaped by living and nonliving parts of an environment, and they can be grouped as terrestrial or aquatic. Terrestrial ecosystems depend on climate. Aquatic ecosystems are divided into freshwater and marine systems, and depth affects water temperature and how much sunlight reaches the water. Terrestrial ecosystems are called biomes. A biome is defined by climate and by the organisms that live there. Near the equator, rainforests have high, aseasonal temperatures and high annual...

trophic levels

Food Chains and Energy Flow

Food chains show how energy and nutrients move through an ecosystem. Each organism holds a trophic level, or a specific place in that chain. The lowest level includes primary producers, which make their own food using energy from the sun or from chemicals. Organisms at the next levels are heterotrophs, which get energy from other organisms below them. Primary consumers are herbivores, and they feed on autotrophs, also called primary producers. Secondary and tertiary consumers are carnivores...

primary production

GPP, NPP, and Ecosystem Energy

Gross primary production and net primary production describe how energy enters and moves through ecosystems. Primary producers, or autotrophs, make their own food. They can do this by photosynthesis or chemosynthesis, and they can also gain energy by consuming other organisms. The rate at which producers capture and store this energy is called gross primary production, or GPP. Not all of the energy in GPP stays available to the rest of the ecosystem. Primary producers use some energy for...

production efficiency

Energy Transfer as Biomass Efficiency

Net production efficiency shows how much energy organisms turn into biomass for the next trophic level. It focuses on the usable energy stored in body tissue, not the energy lost as heat or excreted wastes. This makes it a key idea for understanding energy flow through ecosystems. As energy moves from one organism to the next, only biomass can serve as food for the next trophic level. The rest of the energy is used in metabolism and is lost over time. Net production efficiency, or NPE, is the...

trophic efficiency

Energy Loss in Food Chains

Trophic level transfer efficiency describes how much energy moves from one level of a food chain to the next. It shows why energy drops sharply as organisms eat and are eaten. In most ecosystems, only about 10% of the energy passes on. This energy loss follows the second law of thermodynamics. In living systems, much of the energy is lost as metabolic heat during respiration. Trophic level transfer efficiency, or TLTE, measures this transfer by comparing the energy produced at one trophic...

what are biogeochemical cycles?

Nutrient Recycling in Ecosystems

Nutrient recycling in ecosystems keeps the elements needed for life moving through living and nonliving parts of the environment. Elements such as water, carbon, nitrogen, sulfur, and phosphorus are present in limited amounts, so they must be conserved and reused. These movements are called biogeochemical cycles. These nutrients can exist in several chemical forms. They may spend long periods in the atmosphere, on land, under the land, or in aquatic environments. Decomposition is a key part of...

the water cycle

Water Movement Through Earth Systems

Water movement through Earth systems connects the hydrosphere, the atmosphere, the land, and living things. The hydrosphere includes every place where water is stored or moves. Because water supports living processes, its movement is important for ecosystem dynamics. The cycle starts when the sun warms surface water on land and in the oceans. That water evaporates and enters the atmosphere as vapor. Water can also move into the air by sublimation, which is ice changing directly into vapor, and...

the carbon cycle

Carbon Movement in Living Systems

Carbon moves through living systems and Earth over short and long time scales. It is the basis of all organic matter on Earth, and it cycles through ecosystems by passing between organisms and by moving through rocks, oceans, and the atmosphere. Human activities, including farming and burning fossil fuels, have changed this balance. In the biological carbon cycle, carbon dioxide in the atmosphere reacts with water to form bicarbonate. Primary producers, or autotrophs, use carbon dioxide and...

the nitrogen cycle

Nitrogen in soil and living things moves through ecosystems in several forms. Nitrogen atoms are found in proteins and DNA. Most animals and plants cannot use nitrogen gas, which is the main form of nitrogen on Earth. Nitrogen must first be changed into a usable form by nitrogen-fixing bacteria before it can move through food webs. About 78% of the air we breathe is nitrogen gas, but few organisms can use it in that form. Nitrogen fixation changes nitrogen gas (N2) into ammonia (NH3).

the phosphorus cycle

Phosphorus Movement in Soil and Water

Phosphorus moves through ecosystems mostly as phosphate ions in soil, water, sediment, and rocks. Unlike carbon, water, and nitrogen, it is not found in the atmosphere as a gas. It is also often a limiting nutrient, which means it is in short supply in many environments. Phosphorus is important in DNA, cell membranes, bones, and teeth. It is found in minerals, sediment, volcanic ash, and aerosols. As rocks and sediment weather over time, they release inorganic phosphate. That phosphate then...

the sulfur cycle

Sulfur in Ecosystems and Acid Rain

Sulfur moves through ecosystems as part of the chemical cycle that supports life. It is an important element in proteins and in amino acids such as cysteine, which helps give proteins their structure. On land, sulfur reaches ecosystems in several ways. Weak sulfuric acid can fall with precipitation, sulfur can drop directly from the atmosphere, rocks can weather and release sulfur, and geothermal vents can add it as well. Plants and microorganisms take sulfur up from the soil and change it...

bioremediation

Bioremediation in Soil and Oil Cleanup

Bioremediation uses prokaryotes, fungi, or plants to remove pollutants from the environment. It is a practical way to reduce harmful chemicals in contaminated soil and water. In agriculture, fertilizers and pesticides can leach into groundwater, streams, and lakes. Microbes and bacteria can help break down these toxins. One example is atrazine, an environmental toxin found in many fertilizers, which can be removed from soils by the bacterial species Rhizobium and Tricoderma sp. Bioremediation...

key terms and concepts

Follow nitrogen as it moves from air to soil, plants, and animals, and see how bacteria, fertilizers, and runoff shape the cycle in ecosystems.

Nitrogen in Soil and Living Things | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

La collection JoVE Core Biologie donne vie à la biologie à travers plus de 300 leçons vidéos animées concises et faciles à comprendre qui expliquent les concept clés de la biologie, mais aussi plus de 150 vidéos de scientifiques à l'action effectuant des expériences de recherche dans des laboratoires modernes.

Earth and Environmental Science

Earth's Systems

ESS.EES.2.4

ESS.EES.4.2

Pennsylvania State Academic Standards

Life Science

matter-and-energy-in-organisms-and-ecosystems

Matter and Energy in Organisms and Ecosystems

3.1.9-12.H

3.1.9-12.K

Louisiana Student Standards for Science

High School

Life Sciences

Ecosystems: Interactions, Energy And Dynamics

HS-LS2-4

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

Diversity And Interdependence Of Life

Biodiversity

Tennessee Academic Standards

Ecosystems: Interactions, Energy, and Dynamics

BIO1.LS2.3

Virginia  Standards of Learning

HIgh School

BIO.8

BIO.8.b

Earth Science

ES.11

ES.11.b

LS.5

LS.5.a

LS.9

LS.9.c

Minnesota Academic Standards in Science

2.2.1 9L.2.2.1.1

Texas Essential Knowledge and Skills

Earth Systems Science

112.49.c.11

112.49.c.11.A.

112.49.c.12.

112.49.c.12.E.

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

HS-LS2-3

Earth and Space Science

HS-ESS2-6

Arizona Science Standards

HS+B.L2

HS+B.L2U1.3

HS.L2

HS.L2U1.21

Alabama Course of Study Science

Ecosystems: Interactions Energy and Dynamics

9-12.B.2.7

Environmental Science

9-12.EVS.1.2

Earth and Human Activity

9-12.EVS.4.8

Next Generation Science Standards

Florida Department of Education

SC.912.E.7

SC.912.E.7.1

SC.912.L.17

SC.912.L.17.10

BIO.13

BIO.13.C

Georgia Standards of Excellence

Botany

SBO5.

All Standards

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

B-LS2-5.

Earth and Space Science (ESS)

Earth’s Systems

E-ESS2-7.

SEV1.

SEV1.c

new-york-state-science-learning-standards

New York State Science Learning Standards

HS-LS2-3.

HS-LS2-4.

HS-LS2-5.

Earth and Space Sciences

HS-ESS2-6.

Oceanography

SO6.

SO6.2

SEC4.

SEC4.a

SB5.b

myJoVE Corporation

What are Biogeochemical Cycles?

The most common elements in organic molecules, carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus, are only available in the ecosystem in limited ...

The Water Cycle

The Earth&rsquo;s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, ...

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among ...

Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of ...

The Phosphorus Cycle

Unlike carbon, water, and nitrogen, phosphorus is not present in the atmosphere as a gas. Instead, most phosphorus in the ecosystem exists as compounds, ...

The Sulfur Cycle

Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the ...

Use models to illustrate how processes in organisms contribute to the flow of energy and the cycling of matter within an ecosystem.

What are Populations and Communities?

Populations are groups of individuals of the same species that inhabit a shared environment. Communities include multiple co-existing, interacting ...

Distribution and Dispersion

Ecology is the study of how organisms interact with their environment and with one another. An important aspect of ecology is understanding where species ...

Life Histories

Constrained by limited energy and resources, organisms must compromise between offspring quantity and parental investment. This trade-off is represented ...

Energy Budgets and Reproductive Strategies

Organisms must balance energy intake with the energy required for growth, maintenance, and reproduction. These trade-offs result in a variety of ...

Population Growth

Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with ...

Use models to explain the relationship between the flow of energy and cycling of matter among organisms in an ecosystem.

LS.Bio.4.2

Ecological Niches

All organisms have a position within an ecosystem. The complete set of living and nonliving factors&#x2014;including food resources, climate, and ...

Ecological Succession

Ecological succession is influenced by the processes of facilitation, inhibition, and toleration. Facilitation occurs when early successional species ...

Keystone Species

Measures of species biodiversity, such as richness (i.e., the number of species present) and evenness (i.e., their relative abundance), describe an ...

Symbiosis

Symbiotic relationships are long-term, close interactions between individuals of different species that affect the distribution and abundance of those ...

Competition

When organisms require the same limited resources within an environment, they may have to compete for them. Competition is a net-negative interaction. ...

Predator-Prey Interactions

Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction ...

Ecological Disturbance

An ecological disturbance is a temporary disruption in the environment resulting from abiotic, biotic, or anthropogenic factors, causing a pronounced ...

Use mathematics and computational thinking to explain how interactions between organisms (predator/prey, competition) affect carrying capacity and maintain stability in an ecosystem.

LS.Bio.5.1

Analyze the relationships between matter and energy within ecosystems.

Nitrogen in Soil and Living Things

Description

Transcript

Tags

More videos by Standards