Chapter 5: Assimilation of Inorganic Nutrients Flashcards
nutrient assimilation
incorporation of mineral nutrients into organic molecules
what form of nitrogen cannot be used by a plant
N2 because it is stable and held on by a triple bond
where is most of the nitrogen available in
the atmosphere
phosphorylation
remove phosphorous group and the enzyme will be turned on
what happens when a phosphate is attached
the enzyme is turned off
phosphatase
enzyme that will cleave phosphates off molecules that are nitrate reductase
what does protein kinase do in the nitrate to nitrite assimilation
it phosphorylates the molecule so you can bind a phosphate to it a nitrate reductase which turns it off
what happens when there is too much nitrate in the soil
the plant sends it up the xylem and transports it into the stem
what does nitrite reductase do
converts nitrite into ammonium
nitrate assimilation, within the organelles there is reduction processes that ferredoxin that does what
moves electrons around
what are amides and ureides
compounds that have nitrogen atoms in them
ammonium assimilation
taking the ammonium and introducing it into amino acids
how many enzymes are required to convert ammonium to amino acids
2
transamination
passing amino groups from one molecule to another
free living
not in association with another organism
where are free-living symbiotic bacteria located
in the root system and on the nodules of the plant
under conditions where there is not a lot of nitrogen available what will plants produce
heterocyst
heterocyst
thick walled that does not allow for oxygen to pass through
what kinds of environments does nitrogen fixation require
microanaerobic or anaerobic conditions
explain why nitroginase enyzme cannot be in contact with oxygen
nitrogenase has a high affinity for electrons and oxygen is a strong electron acceptor
what is the one gene associated with biological nitrogen fixation
NOD gene
what is required to make the lipochitin oligosaccharide
three NOD genes to code for specific enzymres
organogenesis
formation of nodules
where does the nodule primordium form
opposite of xylem
what inhibits nodule formation at the phloem
ethylene
where does rhizobial infection occur
at the root hairs
symbiosome
organelle containing the rhizobia
the bacteria is converted into specific cells called what? that do what?
bacteriods; nitrogen fixation
sulfur assimilation
occurs mostly in leaves; enters into the xylem and is transported up the plant to the leaves
symporter
when one of the sulfates is taken up, protons will be taken up
methionine
sulfur in this compound can be used to make other molecules
what is the first step of sulfur assimilation
synthesis of cysteine
cysteine is synthesized by the leaf to make what
glutathione
where does the glutathione go
to the phloem and then moved to other parts of the plant
roughly how much of the energy plants generate is used for nitrogen assimilation
25%
