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 about the secondary protein derivatives, Explain about the Secondar...

Explain about the Secondary Protein Derivatives? These are the products of further hydrolytic cleavage of the protein molecule, Examples include: a) Proteoses: Soluble in wa

What is a centimorgan, What is a centimorgan? The Centimorgan, or The r...

What is a centimorgan? The Centimorgan, or The recombination unit, by convention is a distance between two linked genes that corresponds to 1% of recombination frequency of the

Write in 5-6 lines about food pyramid, Write in 5-6 lines about food pyrami...

Write in 5-6 lines about food pyramid. The diabetes food pyramid divides food into six groups. These groups vary with each other on the basis of si-e occupied in the pyramid.

Biological monitoring to validate that the sterilizer, Q. Biological monito...

Q. Biological monitoring to validate that the sterilizer? The use of biological monitors (spore tests) is the most reliable method to validate that the sterilizer is functionin

What is the role of plant cells, What is the role of Plant Cells? Plant...

What is the role of Plant Cells? Plant cells function essentially in the same manner as other eukaryotic cells, but there are three unique structures which set them apart. Plas

Drinking & driving, DRINKING & DRIVING - It should not be mixed because...

DRINKING & DRIVING - It should not be mixed because alcohol - 1.       Impairs ability to judge distances. 2.       Reduces capacity to coordinate limb muscles. 3.

What are the types of colloidal dispersions, What are the types of colloida...

What are the types of colloidal dispersions Depending upon the relative affinity of the dispersed phase for the dispersion medium, colloidal dispersions are, further divided in

In which condition number of white blood cell decreases, The condition in w...

The condition in which there is a DECREASE in the number of white blood cells in humans is termed as: a) Leukocytosis (pron: lew-kO-sigh-toe-sis) b) Leukopenia (pron: lew-kO

Nutrition in animals, filter feeding mode of nutrition is observed in- a) a...

filter feeding mode of nutrition is observed in- a) amoeba b) euglena c)paramoecium d) all of the above

What are polyclonal antibodies, Antibodies of dissimilar specificities, whi...

Antibodies of dissimilar specificities, which react to the same antigen, are known as polyclonal antibodies.

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