Question

The venom of black widow spiders (Latrodectus mactans) contains an enzyme that hydrolyzes lecithin to the phospholipid lysolecithin. The lysolecithin lyses red blood cells, destroying them. One possible mechanism whereby lysolecithin disrupts the plasma membranes of red blood cells is that it:
A. may act in a manner similar to detergents.

B. is toxic to red blood cells.

C. acts as a second messenger to stimulate apoptosis.

D. binds calcium ions, compromising membrane integrity.

E. None of the above is a possible mechanism.

Answer 1

Answer: Option B) is toxic to red blood cells.

Explanation:

Partial hydrolysis of lecithin by lecithinases (enzyme in black widow spiders and snakes venom) causes the removal of only one fatty acid to yield lysolecithins, which when subjected to the bloodstream by sting as a result of spider bite causes the rupture of red blood cells.

Thus, the mechanism is that it is toxic to red blood cells.