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

Criteria to complete evolutionary branch of vertebrates, What are the six c...

What are the six criteria used to build a complete evolutionary branch of vertebrates? Dichotomy in each of the six following criteria builds the vertebrate evolutionary branch

What are twins, What are twins? Genetically what are the two types of twins...

What are twins? Genetically what are the two types of twins that can be generated? Twins are simultaneously generated (within the mother's uterus) offspring. Twins classify acc

VASCULAR PLANTS., WHAT TRAITS ALLOWED VASCULAR PLANTS TO GROW TALL

WHAT TRAITS ALLOWED VASCULAR PLANTS TO GROW TALL

What is the importance of fungi, What is the Importance of Fungi? Fungi...

What is the Importance of Fungi? Fungi are widely distributed in nature. It is estimated that there are about 1.5 million species of fungi on earth. Fungi are both beneficial a

What is the law of limiting factors, What is the law of limiting factors? H...

What is the law of limiting factors? How would the rate of photosynthesis be affected if the soil water becomes limiting? Describe.

What is structural formula of glycerol, Q. What is structural formula of gl...

Q. What is structural formula of glycerol? To which organic function do these molecules belong? Glycerol is a linear chain of three carbons, the central carbon is bound to one

In which bones can bone marrow chiefly be found, In which bones can bone ma...

In which bones can bone marrow chiefly be found? Is the bone marrow made of osseous tissue? Bone marrow can mostly be found in the internal cavities of flat bones, as the verte

Describe uncontrolled mitotic procedure, Q. What is the uncontrolled mitoti...

Q. What is the uncontrolled mitotic procedure that occurs as disease in pluricellular beings called? Uncontrolled mitotic cell division is known as neoplasia. Neoplasia the for

How to removes hydrogen from fatty acids, Suppose you treated butter with a...

Suppose you treated butter with a fatty acid desaturase, an enzyme that removes hydrogen from fatty acids and creates double bonds. What would happen?

Explain intergenic, Intergenic: Amongs the two genes; for example intergen...

Intergenic: Amongs the two genes; for example intergenic DNA is the DNA found amongs two genes. The term is frequently used to mean non-functional DNA (or at least DNA with no kno

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