Fensom and spanner electroosmotic flow hypothesis, Biology

Assignment Help:

Fensom and Spanner Electroosmotic Flow Hypothesis

In electroosmosis the ions flow across a membrane in response to electrical gradient. Ions pull along water and other contents because of solvent drag. In this hypothesis it is visualised that sap flows in the lumen of sieve element and electroosmosis occurs across the sieve plate. The basic idea of this model is represented in Figure. The pores of sieve are negatively charged and many positive ions are associated with them. The companion cells of consecutive sieve elements are shown to be engaged in K+ uptake and release. This generates a (K+) gradient in the direction of phloem sap flux; the fluxes of other solutes are coupled to K+ flux and move along with the electroosmotic flow from one sieve tube to the next.

1433_Fensom and Spanner Electroosmotic Flow Hypothesis.png

Figure: Active uptake of K+ by the companion cell from its associated sieve tube on the left and secretion of K+ into the sieve tube at the right side by its companion cell generate both e potential difference and a K+ concentration gradient. This causes a now of K+ ions and other solutes from right hand side to left.


Related Discussions:- Fensom and spanner electroosmotic flow hypothesis

Explain the nasopalatine nerve and vessels, Nasopalatine nerve and vessels ...

Nasopalatine nerve and vessels Found in the nasopalatine canal, must be taken care off when placing implants in the maxillary incisor region. Subperiosteal implant placement o

What is the cell theory, Cell theory is a theory that asserts that the cell...

Cell theory is a theory that asserts that the cell is the ingredient unit of the living beings. Before the discovery of the cell, it was not examined that the living beings were

Differences of transposable elements in e. coli, Discuss the similarities a...

Discuss the similarities and differences of transposable elements in E. coli, yeast, plants, and Drosophila.

Implant exposure - implant surgery, Describe Implant exposure ? Sound su...

Describe Implant exposure ? Sound surgical principles to minimize the surgical exposure based on the access required should be employed. A series of surgical approaches to achie

Define cellulose, Cellulose Cellulose is found in plants as microfibr...

Cellulose Cellulose is found in plants as microfibrils (2-20 nm diameter and 100-40,000 nm long). These form the structurally strong framework in the cell walls. Cellulose is

Define absorption of dietary iron, Define Absorption of Dietary Iron? H...

Define Absorption of Dietary Iron? Haem iron is more bioavailable than non-haem iron because it is absorbed intact as a soluble complex by endocytosis (process whereby cells ab

Synapse, SYNAPSE - The point where 2 neurons combine is synapse. It ...

SYNAPSE - The point where 2 neurons combine is synapse. It is of 2 types - (i) Axosomic (between axon & cyton) (ii) Axodendric (between axon & dendron) Axon is term

Headache associated with neurological diseases, Headache Associated with Ne...

Headache Associated with Neurological Diseases Headache is a symptom of many nervous system disorders, usually resulting from the distortion of pain sensitive structures. Commo

Study giude, how many atoms are H2SO4 compound

how many atoms are H2SO4 compound

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd