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

Illustrate about components of an angioplasty system, Q. Illustrate about C...

Q. Illustrate about Components of an Angioplasty System? 1) Guiding catheter: The ideal guiding catheter must have a lumen diameter i.e. at least twice that of the diagnostic c

Explain regulatory enzymes, Explain Regulatory enzymes Regulatory enzy...

Explain Regulatory enzymes Regulatory enzymes:   Citrate  synthase,  isocitrate  dehydrogenase  and a-ketoglutarate dehydrogenase complex are the key  enzymes which  regulate

Definition of epileptic seizures, Definition of Epileptic seizures Epil...

Definition of Epileptic seizures Epileptic seizures are classified as symptomatic seizures if they can be identified with a specific cause, such as infection, trauma, tumor, va

Define the maintenance of weight loss, Define the Maintenance of Weight Los...

Define the Maintenance of Weight Loss? Once an individual has managed to lose weight to a desirable level, it must not be assumed that the weight loss will be maintained automa

Explain the meaning of transfer of culture, Explain the Meaning of Transfer...

Explain the Meaning of Transfer of Culture Transfer of culture can be done from one liquid media to another liquid media or from liquid to solid media or vice versa. The steps

Regeneration - root and shoot morphogenesis, Regeneration - Root and Shoot ...

Regeneration - Root and Shoot Morphogenesis Higher plants have three kinds of regenerative activities; All plants possess inherent ability to regenerate lost parts. Fo

Genetics , write about complementary genes

write about complementary genes

What is the criterion used to classify hosts, What is the criterion used to...

What is the criterion used to classify hosts as intermediate hosts or as definitive hosts? The criterion used to classify hosts as intermediate hosts or as definitive hosts is

Explain cake mix evaluation - performance evaluation, Cake mix evaluation  ...

Cake mix evaluation  Originally, cake mix formulations were very similar to bakery cakes and utilized standard "Hi-Ratio" cake oils; however, development of improved cake mixes

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