8 k kr 11 na h2 p n2o s co n xe o3 no2 i2 nh3 h o h

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Unformatted text preview: 90 Fe – 50,000 Ne 18 Ca He 5 Mg CH4 1.8 K Kr 1.1 Na H2 P N2O S CO N Xe O3 NO2 I2 NH3 H-O-H 460kJ mol-1 H-bonds 23kJ mol-1 Glucose is C6H12O6 Out of 1000 0000 Essential Elements • Definitions – Macronutrients • Needed in relatively high concentrations – Micronutrients • Needed in relative low concentrations – Essential if: • Its absence or deficiency prevents plant from completing life cycle • Cannot be substituted for by another nutrient • Has a specific role in plant metabolism – Alternative classification • Define groups of essential elements based upon function Mineral Nutrition Essential Elements • Relative quantities of macro- and micronutrients • Relative quantitative requirements – Typical concentrations sufficient for plant growth Mineral Nutrition Essential Elements • Relative quantitative requirements – Constituent levels of nutrients in plant tissues Text these are all different way that ppl expressed it. Mineral Nutrition Essential Elements • Relative quantitative requirements – Effects of varying quantities of elements less than 1.5 % N plants cannot grow. then there is critical point where any less or more can decrease growht also you have a point where is a toxic point. different plants have different percent on these two points. Mineral Nutrition Essential Elements Functions • Carbon compounds - Basic structure – C, H, O (not essential mineral nutrients) • Carbohydrates, cellulose • Part of carbon compounds (by covalent bonding = energy) – N and S – amino acids, nucleic acids • Energy storage and structure – P, B – cell walls and phospholipids, Si deposited in cell walls • Ionic forms – K, Ca, Mg,ext l, Mn, Na – used by enzymes as cofactors or have TC Text osmotic functions • Redox reactions – Fe, Zn, Cu, Ni, Mo – used in enzymes Mineral Nutrition Specific Roles of Essential Elements Nitrate, ammonium • Nitrogen (NO3-, NH4+) – Essential to cell division and expansion – Usually taken up as NO3-, but NH4+ is also taken up* – Plants average 2-4% N (dry mass basis) • Quickly incorporated into simple amino molecules – Amino acids -> proteins, purines, pyrimidines -> nucleic acids -> RNA, DNA – Highly mobile in the plant - moves to young tissues Mineral Nutrition Specific Roles of Essential Elements • Nitrogen (NO3-, NH4+) http://commons.wikimedia.org/wiki/File:Nitrogen_Cycle.svg Mineral Nutrition Specific Roles of Essential Elements • Phosphorus (H2PO4-) – Mobile in the plant -> older to younger tissues • ATP, NADPH – Peak phosphorus? read more: http://en.wikipedia.org/wiki/Peak_ph osphorus Mineral Nutrition Specific Roles of Essential Elements the third essential element • Potassium (K+) (potash) means when you burn a plant you get rid of all carbon, etc you will remain the essential stuff. so basically you would burn a plant and put the ash into a pot and anything that dissolved will dissolve in water and basically the rest is garbage and the stuff that dissolved were potassium. – Active uptake and transport – Uptake is temperatu...
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