Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
Criteria for determining essentiality
|
1. necessary for normal development and reproduction through a full life cycle.
2. restoration of growth/reproduction occurs only with that element (no substitute will suffice) 3. must be taken up by the plant and used internally. |
|
Methods for determining essentiality
|
1. study chemical composition
2. hydroponics |
|
First 6 mineral nutrients found by Knops & vonSachs
|
Ca+2, K+, Mg+2, NO3-, PO4-2, SO4-2
|
|
Macroelements
|
Ca+2, K+, Mg+2, H2PO4-, NO3-, SO4-2
|
|
Relative uptake of macroelements in wheat
|
N>K>P>Ca>Mg/S
|
|
Microelements
|
Fe+2, Mn+2, Zn+2, Cu+2, MoO4-2 (molybdenum), Cl-, Boron( BO3-2)
|
|
Nitrogen
|
NO3-, macroelement. amino acids (proteins), nucleic acids (DNA/RNA), chlorophyll
|
|
Phosphorus
|
H2PO4-, macroelement. ATP. nucleic acids (DNA/RNA) and other sugar phosphate. phospholipid.
|
|
Sulfur
|
SO4-2, macroelement. amino acid (methionine & cysteine), Coenzyme A, Fe-S cluster involved in photosynthesis
|
|
Potassium
|
K+, macroelement. main cation in cells (osomotic levels in cytoplasm - turgor). enzyme activation
|
|
Calcium
|
Ca+2, macroelement. secondary messenger, enzyme regulation, cell wall (middle lamella) afftects membranes.
|
|
Magnesium
|
Mg+2, macroelement. chlorophyll, enzyme activation, nucleic acid metabolism, RNA/ribosome structure.
|
|
Iron
|
microelement (Fe+2), chlorophyll synthesis, cytochrome, Fe-S cluster
|
|
Copper
|
microelement (Cu+2), plastocyanin (electron transfer in photosynthesis)
|
|
Manganese
|
microelement (Mn+2), chlorophyll synthesis, necessary for enzyme (oxidase)
|
|
Zinc
|
microelement (Zn+2) - activates enzymes, transcription
|
|
Molybdenum
|
nitrate reductace (reducing and metabolizing nitrogen)
|
|
Manganese
|
chlorophyll synthesis, necessary for oxidase enzyme
|
|
Zinc
|
activate enzyme, transcription
|
|
Molybdenum
|
nitrate reductase (reducing and metabolizing nitrogen)
|
|
Chlorine
|
unknown - photosynthesis, release of oxygen
|
|
Boron
|
unknown
|
|
Sodium
|
needed by mangroves and salt marsh plants
|
|
Silicon
|
some grasses are silica -rich, stinging needed
|
|
Selenium
|
some species in Se-rich soils accumulate Se and become very toxic
|
|
5 Soil Components
|
1. inorganic particles
2. water 3. organic particles 4. air 5. organisms |
|
Soil Particle Size Categories
|
1. coarse sand (0.2 - 2.0 mm)
2. fine sand (0.02 - 0.2 mm) 3. silt (0.002- 0.02 mm) 4. clay (<0.002 - 2 um) |
|
Significance of soil composition
|
Determines amount of water (and dissolved minerals) soil can hold
|
|
What happens after rain?
|
H20 drains into aquifer
|
|
field capacity
|
amount of H20 remaining
|