Phosphorus in Plant Metabolism

Phosphorus is the central element in the energy metabolism of all living organisms; in this process, storage and transfer of chemical energy by formation and degradation of polyphosphate esters with adenosine take place. Phosphorus is not reduced, in contrast to nitrogen and sulfur, but remains in the highest oxidation state and is esterified in this form. It is taken up as H2PO4. In the cell phosphorus is available in this form (Pi) and binds as PC>4+ to carbohydrates forming simple phosphate esters (C-O-P, e.g. in sugar phosphate) or forming energy-rich pyrophosphate (P-P bonds) or diester bridges between carbohydrate groups (C-P-C).

Structural functions: P participates in the formation of

• RNA as a bridge between the ribose-N bases

• phospholipids of membranes.

Metabolic functions:

• energy storage and transfer by polyphosphate esters with adenosine. Di- and triesters are the actual energy storage in the cell (adenosine monophosphate, AMP; adenosine diphosphate, ADP; adenosine triphosphate, ATP)

• energising of binding sites for metabolic turnover. Sugar phosphates (e.g. fructose-1,6-diphosphate) play a decisive role in the regulation of sugar metabolism and triosephos-phates are an important transport metabolite between chloroplast and cytosol (Stitt 1994).

Was this article helpful?

0 0
The Ketosis Plan Diet

The Ketosis Plan Diet

Top Low Carb Internet Guru Speaks Out. An Open Letter To Anyone Who Wants To Lose Up To 20 Pounds In 30 Days The 'Low Carb' Way. 30-Day Low Carb Diet 'Ketosis Plan' has already helped scores of people lose their excess pounds and inches faster and easier than they ever thought possible. Why not find out what 30-Day Low Carb Diet 'Ketosis Plan' can do for you by trying it out for yourself.

Get My Free Ebook

Post a comment