Nitrogen

Definition

Nitrogen is a chemical element with the symbol 'N' and atomic number 7. It is a colorless, odorless gas that makes up about 78% of the Earth's atmosphere and is essential for all living organisms as a fundamental building block of proteins and nucleic acids. In terms of atomic structure, nitrogen has seven protons, seven neutrons, and usually seven electrons, which gives it unique properties that influence how it forms bonds with other elements.

5 Must Know Facts For Your Next Test

1. Nitrogen exists primarily as diatomic molecules (N₂), where two nitrogen atoms are bonded together, making it very stable and non-reactive under standard conditions.
2. Nitrogen fixation is the process by which atmospheric nitrogen is converted into ammonia or related compounds in soil, which is crucial for plant growth.
3. Nitrogen plays a critical role in the structure of DNA and RNA, as it is part of the nitrogenous bases that make up these essential biomolecules.
4. In terms of chemical bonding, nitrogen can form up to three covalent bonds with other elements due to its three unpaired electrons in the outer shell.
5. Despite being abundant in the atmosphere, nitrogen must be transformed into a biologically usable form through processes such as lightning strikes or biological nitrogen fixation by certain bacteria.

Review Questions

• How does nitrogen contribute to the formation of amino acids and nucleotides?
  • Nitrogen is essential for the formation of amino acids, which are the building blocks of proteins. Each amino acid contains an amino group (-NH2) that includes nitrogen. Similarly, nucleotides, which make up nucleic acids like DNA and RNA, also contain nitrogen in their structure as part of the nitrogenous bases. This connection shows how vital nitrogen is for both protein synthesis and genetic material.
• Discuss the significance of nitrogen fixation in ecosystems and its impact on plant growth.
  • Nitrogen fixation is crucial for ecosystems because atmospheric nitrogen (N₂) cannot be directly used by plants. Through this process, specialized bacteria convert nitrogen into ammonia or nitrates, which can then be absorbed by plants. This transformation not only supports plant growth but also contributes to the entire food web since plants serve as primary producers for herbivores and other organisms.
• Evaluate how nitrogen's ability to form multiple bonds influences its role in biological molecules compared to other elements.
  • Nitrogen's ability to form up to three covalent bonds allows it to create complex structures within biological molecules such as proteins and nucleic acids. This multi-bonding capability provides flexibility and stability necessary for the diverse functions these molecules perform in living organisms. Compared to elements like carbon or oxygen, nitrogen adds critical functionality by enabling intricate molecular architectures that are fundamental to life processes.

Related terms

Amino Acids: Organic compounds that serve as the building blocks of proteins and contain nitrogen in their structure.

Nucleotide: The basic structural unit of nucleic acids like DNA and RNA, consisting of a nitrogenous base, a sugar, and a phosphate group.

Covalent Bond:

A type of chemical bond where atoms share pairs of electrons, which is significant in nitrogen's ability to form stable molecules.