Facilitated Diffusion

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What is facilitated diffusion? In membrane, there are protein channels (pores) that allow polar molecules (soluble in water but not soluble in lipids) to move through them. The molecules that move through these channels never come into contact with the hydrophobic layer or the membrane's polar surface because these channels provide a continuous pathway for molecules that are moving through them. In this type of diffusion, like simple diffusion, no energy is consumed. Large and polar molecules require help to pass through the membrane. This help is done by a type of protein called carrier (transport) protein . To pass through the membrane, a molecules binds (temporarily) with carries protein in lipid bilayer and is transported from an area of higher concentration to an area of lower concentration.  Related topics: Simple Diffusion
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What is cholera?its causes and symptoms.

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Cholera

Cholera is infection(invasion of an organism's body tissues by disease causing agents) of small intestine.It causes severe watery diarrhea,which can lead to dehydration and even may cause death if left untreated.It occurs by eating food or drinking water contaminated with a bacterium called Vibrio cholerae.

Symptoms of cholera   

                                                                                                      Its symptoms ranges from none,to mild,to severe.The most classic symptom is large amount of watery diarrhea that lasts for few days.Vomiting and muscle cramps may also be caused.Severe diarrhea leads to severe dehydration and electrolyte imbalance.It may cause sunken eyes,cold skin,wrinkling of hands and feet,decreased skin elasticity and skin may turn bluish.
 

Bacterium Vibrio cholerae,causes of cholera  

 
  Vibrio cholerae is a Gram-negative,comma-shaped bacterium(Plural:bacteria).It lives in brackish or saltwater where they attach themselves easily to the chitin-containing shells  crabs,shrimps and other selfish.Some of V.cholerae cause the disease cholera.Consumption of undercooked or raw marine life species causes cholera.V.cholera is facultative anaerobic(an organism that makes ATP by aerobic respiration in the presence of oxygen,but  also capable of carrying fermentation if oxygen is absent).It has a flagellum(A lash-like appendage that protrudes from cell body of certain bacteria and eukaryotes) at one cell pole as well as pili(Singular:pilus;a hair-like structure  on the surface).                                                                                       It can cause diarrhea and vomiting in the host within some hours to 2-3 days after being ingested.It was first known as cause of cholera by Italian anatomists Filippo Pacini and Catalan Joaquim Balcells i Pascal in 1854.

 

 classification of Vibrio cholerae is as

Domain:          Bacteria

Phylum:           Proteobacteria

Class:               Gammaproteobacteria

Order:             Vibrionales

Family:                      Vibrionaceae

Genus:             Vibrio

Species:           V.cholerae  

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