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

What is the kind of digestive system of echinoderms, Q What is the kind of ...

Q What is the kind of digestive system of echinoderms? Echinoderms present a complete digestive system with anus and mouth. Q. Do sea urchins have teeth? Sea urchins ha

Explain clostriduim botulinum, Q. Explain Clostriduim botulinum? Clostr...

Q. Explain Clostriduim botulinum? Clostriduim botulinum is widely distributed in soil and marine sediments throughout the. world. It is also found in the intestinal tract of a

The z-gene codes for permease, Select the two correct statements out of the...

Select the two correct statements out of the four (a - d) given below about lac operon. 1. Glucose or galactose may bind with the repressor and inactivate it 2. In the absenc

State about charles elton, What evidence did Charles Elton collect that sug...

What evidence did Charles Elton collect that suggested that fluctuations in hare and lynx populations were related? What other evidence shows that these fluctuations ma

Control of air pollution, Air pollution can be controlled by two fundamenta...

Air pollution can be controlled by two fundamental ways. Preventive technique: Important measure to control air pollution Suitable fuel having low sulphur content shoul

Phenotypic classes, 1. A pure-breeding black, smooth guinea pig was mated t...

1. A pure-breeding black, smooth guinea pig was mated to a pure-breeding white, rough female. They produced several litters, and eventually, five males and twenty females resulted

Describe any three adaptations of mangroves, Name and describe any three ad...

Name and describe any three adaptations of mangroves to the conditions prevailing in the Sunderbans.

Explain offspring of heterozygous for autosomal trait mates, If a male who ...

If a male who is heterozygous for an autosomal trait mates with a female who is also heterozygous for that trait, what percent of their offspring are probable to be heterozygous fo

Ribosome in the translation of one mrna molecule, Q. How many of the same p...

Q. How many of the same proteins are made at the same time by each ribosome in the translation of one mRNA molecule? How does successive protein production occur in translation?

Determine the members of kingdom plantae, Normal 0 false fals...

Normal 0 false false false EN-IN X-NONE X-NONE

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