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

Phylum protozoa, distinguishing charecters and classification of protozoa u...

distinguishing charecters and classification of protozoa upto phyla

Hydration control by active pump mechanisms in corneal, How is hydration co...

How is hydration control by active pump mechanisms responsible in the corneal hydration? Hydration Control by Active Pump Mechanisms: a) Na/K ATPase pump, which is more acti

Distribution coefficient -terminology used in chromatography, Distribution ...

Distribution Coefficient - Terminologies used in Chromatography? During the purification or separation of the biomolecules it should be kept in mind that two important factors

Explain types of dietary adaptations for trerapieutic needs, Types of dieta...

Types of dietary adaptations for trerapieutic needs Normal nutrition is the foundation upon which therapeutic modifications are based. We  have already discussed  in  previous

Density - population parameters and regulation, Density - Population Parame...

Density - Population Parameters and Regulation Density is defined as number of individuals or population biomass per unit of area or volume at any given time. Biomass refers t

Human impact on carbon cycle, Human Impact on Carbon Cycle Human activ...

Human Impact on Carbon Cycle Human activities have greatly influenced the carbon cycle. The discharge of CO 2 , into the atmosphere is steadily increasing owing to burning of

Explain about the basidiomycota - fungi, Explain about the Basidiomycota - ...

Explain about the Basidiomycota - Fungi? Basidiomycota - Fungi in this division are called basidiomycetes or club fungi. Sexual structure is known as basidium, which is club-sh

Glands and its types, Glands A cell, tissue or organ which secretes ...

Glands A cell, tissue or organ which secretes specific chemical secretion is known as a gland. The glands develop from the epithelium tissues. The glands are classifi

How is the brain involved in the immune system, How is the brain involved i...

How is the brain involved in the immune system? A. Immune cells that constitute body's biological defense against infections and toxins, have many things in common with nerve c

Gastroesophageal reflux, Q. Show Gastroesophageal reflux? Obesity is th...

Q. Show Gastroesophageal reflux? Obesity is thought to be another potential predisposing factor to gastroesophageal reflux or GERD. Maintenance of ideal weight for age may help

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