Phospholipase is an enzyme that cleaves the phosphate head group off a phospholipid molecule. The plasma membrane is not, however, permeable to the enzyme. Imagine a cell where phospholipid A is present in the layer of phospholipids facing the exterior of the cell, and phospholipid B is present in the layer of phospholipids facing the interior of the cell. After adding phospholipase to the medium in which the cell is growing, what would you expect to find in the fluid surrounding the cell?
a. phosphate head groups from neither phospholipids A nor B
b. phosphate head groups from both phospholipids A and B
c. the phosphate head group from phospholipid B only
d. the phosphate head group from phospholipid A only
Ans: d. the phosphate head group from phospholipid A only
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