Question

3. Many snake venoms contain a phospholipase A2 enzyme that hydrolyzes the C2 fatty acid from a phospholipid to yield a corresponding lysophospholipid with a single hydrocarbon tail. High concentrations of lysophospholipids can disrupt membrane function and lead to cell death. 0 0 CH-0-0-R R-0-0-CH 0 CH2-0-P-0-X 0 Phospholipid HOR -C-OH free fatty acid CH-0-C-R + H-0ẠCH 0 phospholipase A2 CH,-0-2--0-X 0 Lysophospholipid Figure 2. Action of phospholipase A2. X=polar head group. R=long hydrocarbon tails. a. Phospholipids do not form micelles (i.e. single monolayer structures) like free fatty acids. Why? b. Explain how lysophospholipids might disrupt lipid bilayers and lead to cell lysis (i.e. breakage of the bilayer membrane). (Hint: part a might contain a clue)

Answer 1

=) a) Phospholipid is an amphipathic molecule i.e. it has both hydrophobic and hydrophyfic Component. As shown in figure e Phospholipich contain a dyrerd molecule, two fully- auid chain which are unchanged, nou-selur tail and hydrophobic in nature and the phosphate group, which is nepatively charged polar head and it is hydrophylic in nature Amicelle is a stable formation of graphifchate melecule or molecules having a polar head and nowosolare tail. Since in phospholifich there are two hydrophobler tails, that came the over-crowding during the micelle, formation and hence they prefer to form " bilazers" instead of miceller Cie. spherical-structure) 6) lyrophospholipids are the derivatives of phospholipide in which one of the acyl-derivative of school holipid hon been removed or hydrofzed in the preence of Phospholipare Az engyme to release the fatty acich and from the Lysoplosiholifich an shown in figme &. This activity leach to the depradation of phosphelified and hence their stable bilger structure that form the cell-membrane of the cells. It would cause the hemolzit or loss of the integrity of the bilayer membrane and lead to cell lyris (le breakage of the bilager membrane).