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  2. Nitrogen compounds - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_compounds

    The amount of nitrogen in a chemical substance can be determined by the Kjeldahl method. [21] In particular, nitrogen is an essential component of nucleic acids, amino acids and thus proteins, and the energy-carrying molecule adenosine triphosphate and is thus vital to all life on Earth. [20]

  3. CHNOPS - Wikipedia

    en.wikipedia.org/wiki/CHNOPS

    Graphic representation of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. CHNOPS and CHON are mnemonic acronyms for the most common elements in living organisms. "CHON" stands for carbon, hydrogen, oxygen, and nitrogen, which together make up more than 95 percent of the mass of biological systems. [1] "CHNOPS" adds phosphorus and ...

  4. Alkaloid - Wikipedia

    en.wikipedia.org/wiki/Alkaloid

    The boundary between alkaloids and other nitrogen-containing natural compounds is not clear-cut. [14] Most alkaloids are basic, although some have neutral [15] and even weakly acidic properties. [16] In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen or sulfur.

  5. Nitrogen - Wikipedia

    en.wikipedia.org/wiki/Nitrogen

    Nitrogen is a chemical element; it has symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System.

  6. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]

  7. Urea - Wikipedia

    en.wikipedia.org/wiki/Urea

    Urea serves an important role in the cellular metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. Urea is Neo-Latin, from French urée, from Ancient Greek οὖρον (oûron) 'urine', itself from Proto-Indo-European *h₂worsom.

  8. Bioinorganic chemistry - Wikipedia

    en.wikipedia.org/wiki/Bioinorganic_chemistry

    About 99% of mammals' mass are the elements carbon, nitrogen, calcium, sodium, chlorine, potassium, hydrogen, phosphorus, oxygen and sulfur. [3] The organic compounds (proteins, lipids and carbohydrates) contain the majority of the carbon and nitrogen and most of the oxygen and hydrogen is present as water. [3]

  9. Carbon-based life - Wikipedia

    en.wikipedia.org/wiki/Carbon-based_life

    Carbon compounds occur naturally in great abundance on Earth. Complex biological molecules consist of carbon atoms bonded with other elements, especially oxygen and hydrogen and frequently also nitrogen, phosphorus, and sulfur (collectively known as CHNOPS). [2] [3]