Search results
Results from the WOW.Com Content Network
Nitrogen is a fundamental chemical component of amino acids, the molecular building blocks of protein. As such, nitrogen balance may be used as an index of protein metabolism. [1] When more nitrogen is gained than lost by an individual, they are considered to have a positive nitrogen balance and be in a state of overall protein anabolism.
Toxic in some forms. [11] nitrogen: 7: 5: Ubiquitous, essential for all forms of life; all proteins and nucleic acids contain substantial amounts of nitrogen. [11] Toxic in some forms. [11] osmium: 76: 1a: None known. [11] Osmium is very rare, substantially more so than any element essential to life. [3] The oxide is toxic to humans. [11 ...
The need for nitrogen is addressed by requirements set for protein, which is composed of nitrogen-containing amino acids. Sulfur is essential, but again does not have a recommended intake. Instead, recommended intakes are identified for the sulfur-containing amino acids methionine and cysteine .
Parts-per-million cube of relative abundance by mass of elements in an average adult human body down to 1 ppm. About 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium ...
Most plants, therefore, require nitrogen compounds to be present in the soil in which they grow. This is made possible by the fact that largely inert atmospheric nitrogen is changed in a nitrogen fixation process to biologically usable forms in the soil by bacteria. [51]
Nitrogen is present in the environment in a wide variety of chemical forms including organic nitrogen, ammonium (NH + 4), nitrite (NO − 2), nitrate (NO − 3), nitrous oxide (N 2 O), nitric oxide (NO) or inorganic nitrogen gas (N 2). Organic nitrogen may be in the form of a living organism, humus or in the intermediate products of organic ...
[36] [37] The amount of protein required in a person's diet is determined in large part by overall energy intake, the body's need for nitrogen and essential amino acids, body weight and composition, rate of growth in the individual, physical activity level, the individual's energy and carbohydrate intake, and the presence of illness or injury.
Proteins are the basis of many animal body structures (e.g. muscles, skin, and hair) and form the enzymes that control chemical reactions throughout the body. Each protein molecule is composed of amino acids which contain nitrogen and sometimes sulphur (these components are responsible for the distinctive smell of burning protein, such as the ...