CICLO DO NITROGÊNIO | Como Funciona?

Summary

This video explains the nitrogen cycle, starting with the abundance of nitrogen in the atmosphere, making up 78% of the air. Despite its inert nature, nitrogen is converted into usable forms like ammonia, nitrite, and nitrate through bacteria. These forms are absorbed by plants, entering the food chain through herbivores and carnivores. The video also covers the processes of ammonification, nitrification, and denitrification. It highlights the importance of nitrogen for plant growth, animal nutrition, and the ecosystem's balance, warning about the environmental impact of excessive nitrogen from fertilizers leading to eutrophication.

Takeaways

• 😀 Nitrogen (N2) is the most abundant gas in the atmosphere, making up about 78% of the air.
• 😀 Nitrogen is chemically inert, which means it is not easily assimilated by living organisms.
• 😀 Certain plants, especially legumes like beans, soybeans, and lentils, can fix nitrogen from the air through a relationship with nitrogen-fixing bacteria.
• 😀 Free-living bacteria in the soil also help transform nitrogen into usable forms like ammonia, nitrite, and nitrate.
• 😀 The nitrogen cycle can be divided into four key processes: fixation, ammonification, nitrification, and denitrification.
• 😀 Nitrogen fixation involves nitrogen-fixing bacteria transforming atmospheric nitrogen into ammonia, nitrite, and nitrate, which plants can use.
• 😀 Ammonification is the process where animal waste, particularly urea, is transformed into ammonia by soil bacteria.
• 😀 Nitrification is carried out by nitrifying bacteria, which convert ammonia into nitrates, important for plant growth.
• 😀 Denitrification is the process where denitrifying bacteria convert nitrates in the soil back into nitrogen gas, returning it to the atmosphere.
• 😀 Nitrogen is crucial for plants, animals, and humans because it is a key component of proteins and DNA.
• 😀 Excessive nitrogen compounds in the soil, often due to fertilizer use, can lead to environmental issues like eutrophication, which disrupts aquatic ecosystems.

Q & A

What is the most abundant gas in Earth's atmosphere?

Nitrogen (N2) is the most abundant gas in Earth's atmosphere, comprising about 78% of the air.

Why is nitrogen not easily assimilated by living organisms?

Nitrogen is chemically inert and does not react easily, making it difficult for living organisms to assimilate it.

Which plants are capable of fixing nitrogen from the air?

Leguminous plants such as beans, soybeans, and lentils are capable of fixing nitrogen from the air through a symbiotic relationship with nitrogen-fixing bacteria.

What role do nitrogen-fixing bacteria play in the nitrogen cycle?

Nitrogen-fixing bacteria either live freely in the soil or are associated with the roots of leguminous plants, where they convert atmospheric nitrogen (N2) into usable forms like ammonia, nitrite, and nitrate.

What are the main steps involved in the nitrogen cycle?

The nitrogen cycle includes four main processes: nitrogen fixation, ammonification, nitrification, and denitrification.

What happens during the process of ammonification?

During ammonification, urea, a waste product from animal metabolism, is broken down by soil bacteria into ammonia.

How does nitrification contribute to the nitrogen cycle?

Nitrification is the process in which nitrifying bacteria in the soil convert ammonia into nitrates, which are essential for plant growth.

What is denitrification, and why is it important?

Denitrification is the process by which denitrifying bacteria convert nitrates back into nitrogen gas (N2), releasing it into the atmosphere, completing the nitrogen cycle.

Why is nitrogen important for plants and animals?

Nitrogen is crucial for plant growth as it is a key component of proteins and DNA. Animals obtain nitrogen directly or indirectly from plants, which are part of the food chain.

What environmental issue can arise from excess nitrogen in the soil?

Excess nitrogen in the soil, often due to fertilizer use or animal activity, can lead to nutrient imbalances in aquatic ecosystems, causing algae blooms and a phenomenon called eutrophication.