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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 ...
Carbon-to-nitrogen ratios indicate the degree of nitrogen limitation of plants and other organisms. They can identify whether molecules found in the sediment under study come from land-based or algal plants. [1] Further, they can distinguish between different land-based plants, depending on the type of photosynthesis they undergo.
The cyclic light-dependent reactions occur only when the sole photosystem being used is photosystem I. Photosystem I excites electrons which then cycle from the transport protein, ferredoxin (Fd), to the cytochrome complex, b 6 f, to another transport protein, plastocyanin (Pc), and back to photosystem I. A proton gradient is created across the ...
However, N 2 is unavailable for use by most organisms because there is a triple bond between the two nitrogen atoms in the molecule, making it almost inert. In order for nitrogen to be used for growth it must be "fixed" (combined) in the form of ammonium (NH + 4) or nitrate (NO − 3) ions. The weathering of rocks releases these ions so slowly ...
Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N 2) depend on the ability to assimilate nitrate or ammonia for their needs. Other organisms, like animals, depend ...
Relationship of phosphate to nitrate uptake for photosynthesis in various regions of the ocean. Note that nitrate is more often limiting than phosphate. The Redfield ratio or Redfield stoichiometry is the consistent atomic ratio of carbon, nitrogen and phosphorus found in marine phytoplankton and throughout the deep oceans.
Another closely related quantity is the net postprandial protein utilization (NPPU), which is the maximum potential NPU of a dietary protein source under ideal conditions. [1]: 12 The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is a more modern rating for determining protein quality, and the current ranking standard used by the FDA.
Nitrogen is one of the more limiting nutrients and the addition of nitrogen stimulates the photobiont, building up its cell, which subsequently increases its photosynthesis and its carbon input. Multiple nitrogen compounds can be assimilated by lichens, such as NH 4 +, NO 3 − and organic nitrogen compounds. [8]