“Absorption Theory Involved In Nutrient Uptake and its Physiology and its Importance”.pptx

“Absorption Theory Involved In Nutrient Uptake and its Physiology and its Importance”.

1. Topic on Department of Plant Physiology “Absorption Theory I nvolved I n Nutrient U ptake and its Physiology and its Importance ”

2. Uptake of nutrients   :- A n A ctive process. Nutrient uptake is the mechanism by which plants capture all those elements that are essential for their growth . Plant uptake is water taken from the groundwater flow and soil moisture. Only 1% of water the plant draws up is used by the plant.

3. CONT..

4. Absorption theory involved in nutrient uptake Passive Absorption: Absorption of ions without the use of metabolic energy is known as passive absorption. This type of absorption is carried out by purely physical forces .

5. Mass Flow:- The pressure flow hypothesis, also known as the mass flow  hypothesis. It is the best-supported theory to explain the movement of sap through the phloem . Movement of phloem sap occurs by bulk flow (mass flow) from sugar sources to sugar sinks.

6. 2 . Ion-Exchange It is process of mineral absorption, the ions adsorbed on the surface of the root can exchange with the ions of the same charge from the soil solution.

7. cont … 1. Contact Exchange Theory :- According to this theory, the ions adsorbed on the surface of root cells and clay particles (or clay micelles) are not held tightly but oscillate within small volume of space. 2. Carbonic Acid Exchange Theory : - According to this theory, the CO 2  released during respiration of root cells combines with water to form carbonic acid (H 2 CO 3 ).

8. Donnan equilibrium   describes the  equilibrium  that exists between two solutions that are separated by a membrane. The membrane, however, does not allow the passage of all the ions present in the solutions and is thus a selectively permeable membrane. 3. Donnan Equilibrium :-

9. Active Absorption :- Absorption of ions with the use of metabolic energy is known as  active absorption . Absorption of water by roots with the help of  adenosine triphosphate , generated by the root  respiration as the root cells actively take part in the process.

10. . Carrier Concept: According to this theory the plasma membrane is impermeable to free ions. But some compound present in it acts as carrier and combines with ions to form carrier-ion-complex which can move across the membrane. On the inner surface of the membrane this complex breaks releasing ions into the cell while the carrier goes back to the outer surface to pick up fresh ions.

11. Bennet -Clark’s Protein-Lecithin Theory: In 1856,  Bennet  – Clark suggested that because the cell membranes chiefly consist of phospholipids and proteins and certain enzymes seem to be located on them, the carrier could be a protein associated with the phosphatide called as lecithin .

12. B) Cytochrome Pump Theory Lundegardh and Burstrom (1933) believed that there was a definite correlation between respiration and anion absorption. C ytochrome pump theory which is based on the following assumptions: The mechanism of anion and cation absorption is different . Anions are absorbed through cytochrome chain by an active process. Cations are absorbed passively.

13. IMPORTANCE : Active transport  is important because it allows the cell to move substances against the concentration gradient . P assive transport substances simply move from an area of higher concentration to an area of lower concentration, which does not require the input of energy . Mass flow  is the movement of dissolved nutrients into a plant as the plant absorbs water for transpiration. This is important for the transport of phosphorus and potassium .   Ion exchange  resins are useful for the removal of water problems including hard water, scale buildup, nitrates, arsenic and more . Donnan membrane equilibrium has important applications in colloid chemistry and in the technologies of leather and gelatin, but above all in the understanding of the living cell, where it can give a quantitative account of ionic equilibria both within the cell and between the cell and its environment. Carrier proteins "carry" the ion or molecule across the membrane by changing shape after the binding of the ion or molecule .  Importance of transpiration and the role of chlorophyll in plants. Cytochrome pump theory , the anion is absorbed through an active process whereas cation is absorbed through a passive process.

14. . Related Articles : Absorption of Solute by Plants | Botany . Absorption of Mineral Salts by Higher Plant (With Diagram) .