Phosphorus (p) - macronutrients, Biology

Phosphorus (P) - Macronutrients

In soil, phosphorus occurs almost exclusively in the form of orthophosphate. Substantial amount of P is associated with the soil organic matter. The major P-containing ions in soil solutions are HPO2-4 and H2PO4. Roots are capable of absorbing phosphate from solution low in phosphate content. The phosphate content of roots and xylem sap is about 100-1000 fold higher than that of the soil solution. This shows that phosphate is absorbed by plants against a very steep concentration gradient. Phosphate is highly mobile in the plant and can be translocated in upward or downward direction. The inorganic form of phosphate found in plants are orthophosphate and to a minor extent, pyrophosphate. The organic form of phosphates are compounds in which the orthophosphate is esterified with hydroxyl groups of sugars and alcohols or bound through a pyrophosphate bond to another phosphate group. You know that phosphorylated sugars and alcohols are the major intermediary compounds of metabolism.

Phosphate is also present in phospholipids. The nucleotide phosphates - ATP, UTP, GTP, CTP supply energy to various endergonic processes including active ion uptake and the synthesis of various organic compounds. Another important phosphorus containing compound is phytin which is mainly found in seeds. It is Ca or Mg salt of Phytic acid and is formed during seed formation. Phytic acid is the hexaphosphoric ester of inositol. Immediately after pollination there is an increase in P transport towards the developing seeds. Phosphorus in the phytin of seeds is regarded as a P reserve. During seed germination phytin is mobilised and converted into other phosphate forms that are needed in the metabolism of young plants. Plants suffering from P deficiency are retarded in growth. In cereals tillering is reduced. Generally, the symptoms of P deficiency appear in the older leaves which become darkish green in colour. The stems of many annual plant species suffering from P deficiency develop reddish colour due to enhanced formation of anthocyanin pigments.

Posted Date: 1/17/2013 2:49:08 AM | Location : United States







Related Discussions:- Phosphorus (p) - macronutrients, Assignment Help, Ask Question on Phosphorus (p) - macronutrients, Get Answer, Expert's Help, Phosphorus (p) - macronutrients Discussions

Write discussion on Phosphorus (p) - macronutrients
Your posts are moderated
Related Questions
Post-operative care of teeth After implant surgery, patients should be warned to expect:  Some swelling and possibly bruising.  Some discomfort which can usually be contr

Exchange of oxygen, nutrients, carbon dioxide and waste products from mother to fetus takes place through diffusion across the: a) Chorionic villi (pron: core-e-on-ick villi)

Comparing toxicity and the requirement for dilution in water how different are the ureotelic and the uricotelic excretions? What are some examples of animals that present these res

Explain in details Amino Acid? Amino Acids :   There are 20 common amino acids, with a few more found in lower organisms. Adult humans require a diet that includes at least 8

A 16 year old boy named Jake was admitted into the emergency room complaining of headache, fever, stiffness of abdominal muscles and difficulty swallowing. The doctor on staff bega

Explain Mid-diastolic and Lafe Diastolic (Pre Systolic) Sounds ? Mid-diastolic sounds are S3 sounds and late diastolic (pre systolic) sounds are S3 sounds. Pre systolic Pacema

RECORDS AND REPORTS: The principles of administration are described as  'POSDCORB'.  The  'R' stands for recording and reporting. Recording and reporting is related to all oth

What is the function of the umbilical cord? The umbilical cord haves blood vessels which convey blood among the fetus and the placenta.

Q. What do you mean by Current Impediments? Given the impressive list of past achievements, we expect that quantitative process to biological problems will continue to repay us

TYPES OF EGGS Different species of animal has different type of eggs. They are classified on the following basis - 1 .         ON THE BASIS OF AMOUNT OF YOLK On the ba