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An essential amino acid is an amino acid that is required by an organism but cannot be synthesized de novo by it, and therefore must be supplied in its diet. Out of the twenty standard protein-producing amino acids, nine cannot be endogenously synthesized by humans: phenylalanine , valine , threonine , tryptophan , methionine , leucine ...
Water is an inorganic compound with the chemical formula H 2 O.It is a transparent, tasteless, odorless, [c] and nearly colorless chemical substance.It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent [20]).
Structure of the Mn 4 O 5 Ca core of the oxygen-evolving site in plants, illustrating one of many roles of the trace mineral manganese. [38] The list of minerals required for plants is similar to that for animals. Both use very similar enzymes, although differences exist. For example, legumes host molybdenum-containing nitrogenase, but animals ...
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids.The term excludes seawater and brackish water, but it does include non-salty mineral-rich waters, such as chalybeate springs.
The root cells behave as an ideal osmotic pressure system through which water moves up from the soil solution to the root xylem along an increasing gradient of D.P.D. (suction pressure, which is the real force for water absorption).
Microbiological parameters include coliform bacteria, E. coli, and specific pathogenic species of bacteria (such as cholera-causing Vibrio cholerae), viruses, and protozoan parasites. Originally, fecal contamination was determined with the presence of coliform bacteria , a convenient marker for a class of harmful fecal pathogens .
Nutrients in the soil are taken up by the plant through its roots, and in particular its root hairs.To be taken up by a plant, a nutrient element must be located near the root surface; however, the supply of nutrients in contact with the root is rapidly depleted within a distance of ca. 2 mm. [14] There are three basic mechanisms whereby nutrient ions dissolved in the soil solution are brought ...
According to Lunine, "oceans" have been defined as "stable, globe-girdling bodies of liquid water." [13] In addition, "Ocean worlds is the label given to objects in the solar system that host stable, globe-girdling bodies of liquid water," in contrast to the terms "'ocean planet' and 'water world', both of which refer to exoplanets (planets orbiting other stars) with substantial mass fractions ...