Nitrogen

Definition

Nitrogen is a chemical element with the symbol 'N' and atomic number 7, representing a crucial component of amino acids and nucleic acids. It makes up about 78% of the Earth's atmosphere and plays a vital role in the building blocks of life, influencing both biological and chemical processes. Its presence is fundamental for the synthesis of proteins and DNA in living organisms, as well as in various metabolic pathways.

5 Must Know Facts For Your Next Test

1. Nitrogen is essential for the formation of amino acids, which are the building blocks of proteins that perform critical functions in organisms.
2. In plants, nitrogen is primarily absorbed from the soil in the form of nitrate (NO3-) or ammonium (NH4+), both of which are necessary for their growth and development.
3. Nitrogen is a key element in nucleic acids, which include DNA and RNA; these molecules are crucial for heredity and protein synthesis.
4. The nitrogen cycle describes the movement of nitrogen through the environment, involving processes like fixation, nitrification, and denitrification.
5. Excess nitrogen from agricultural fertilizers can lead to environmental issues such as water pollution and algal blooms due to runoff into waterways.

Review Questions

• How does nitrogen contribute to the structure of proteins and nucleic acids?
  • Nitrogen plays an essential role in the structure of proteins by being a key component of amino acids, which link together to form proteins necessary for various biological functions. Additionally, nitrogen is found in nucleic acids like DNA and RNA, where it forms part of the nitrogenous bases that encode genetic information. This connection highlights how vital nitrogen is for both the composition of proteins and the preservation of genetic material in living organisms.
• Discuss the significance of nitrogen fixation in agricultural practices and its impact on plant nutrition.
  • Nitrogen fixation is significant because it converts atmospheric nitrogen into forms that plants can use, such as nitrate or ammonium. This process is often facilitated by symbiotic bacteria in root nodules of legumes or through free-living soil bacteria. By enriching soil with accessible nitrogen, this natural process boosts plant growth and productivity, reducing reliance on synthetic fertilizers while promoting sustainable agricultural practices.
• Evaluate how human activities have altered the nitrogen cycle and the subsequent effects on ecosystems.
  • Human activities, especially through the use of synthetic fertilizers in agriculture, have significantly altered the nitrogen cycle by introducing excess nitrogen into ecosystems. This disruption can lead to nutrient pollution in waterways, causing harmful algal blooms that deplete oxygen levels and harm aquatic life. The overabundance of nitrogen also affects terrestrial ecosystems by altering species composition and disrupting natural nutrient balances, ultimately impacting biodiversity and ecosystem health.

Related terms

Amino Acids: Organic compounds that serve as the building blocks of proteins, which are essential for various biological functions.

Nitrogen Fixation: The process by which atmospheric nitrogen is converted into a usable form by certain bacteria and plants, making it available to living organisms.

Nucleic Acids: Biopolymers, such as DNA and RNA, that store and transmit genetic information, containing nitrogenous bases as key components.