Answer:
The image describe the mechanism of action of cholera
Step-by-step explanation:
Cholera toxin is a potent enterotoxin produced by the bacterium Vibrio cholerae, the causative agent of cholera. The toxin is composed of two subunits: A and B. Subunit B is responsible for binding to specific receptors on the surface of intestinal epithelial cells, while subunit A is responsible for the enzymatic activity that results in the toxic effects.
The mechanism of action of cholera toxin can be described as follows:
Subunit B binds to GM1 gangliosides, a type of molecule found on the surface of intestinal epithelial cells. This binding is specific and allows the toxin to target the cells of the small intestine.
Once the toxin has bound to the GM1 gangliosides, it is internalized by the cell in a process called endocytosis. This results in the formation of an endosome, a compartment within the cell that contains the toxin.
Subunit A is then able to enter the cytoplasm of the cell and bind to a specific type of molecule called an ADP-ribosylating factor.
4.The ADP-ribosylating activity of subunit A results in the modification of a specific type of G protein, called the Gs protein. This modification prevents the Gs protein from functioning normally and leads to an increase in cyclic AMP (cAMP) levels in the cytoplasm of the cell.
Elevated cAMP levels activate a type of ion channel in the plasma membrane of the cell, which allows the entry of chloride ions into the cell. This results in an increased secretion of water and electrolytes into the lumen of the intestine, leading to severe diarrhea.
T.he loss of water and electrolytes from the body can lead to dehydration, electrolyte imbalances, and other serious complications if not properly managed.
In conclusion, the mechanism of action of cholera toxin involves the specific targeting of intestinal epithelial cells, the internalization of the toxin, the modification of a specific G protein, and the subsequent increase in cAMP levels and chloride ion secretion, resulting in severe diarrhea and other complications.