BIOA02H3 Lecture Notes - Lecture 7: Root Hair, Biogenic Substance, Alkali Soil
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BIOA02H3 Full Course Notes
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Document Summary
Hydrogen is the most important building block of plants. Hydrogen, carbon and oxygen makes 96% of plants: concentration in dry matter shows water and carbon dioxide takes up 96% Intermediate elements (n, k ca, mg, p, s, si) make up 3. 6: macronutrients: required in relatively large amounts. Lower elements (cl, fe, b, mn, na, zinc. Ni, mo) make up 0. 4: micronutrients: required in relatively low amounts. Absence of micro and macronutrients prevents plant from completing its life cycle. N,p, k are the most limiting nutrients under average conditions. Nitrogen: essential building block for life, basic metabolism, photosynthesis. Chlorophyll a and b both contain nitrogen. Dna also contains nitrogen: atmospheric overabundance (78% n2) There is enough energy and pressure to create nitrate from atmosphere. Free living soil bacteria take up atmospheric nitrogen and when they decompose into amino acids ammonia nitrite nitrate.
