Q. Two membrane preparations have been derived from plasma membrane of erythrocytes and are present in a buffer solution:

(1) right-side-out membrane vesicles, in which exoplasmic leaflet of the vesicle faces the buffer (equivalent in orientation to that of the exoplasmic leaflet of the intact plasma membrane); and

(2) inside-out membrane vesicles in which the exoplasmic leaflet faces the interior of vesicles.

Annexin V is a protein that binds to phosphatidylserine, one of the phospholipids present in cell membranes.

Fluorescently labeled annexin V is mixed with each vesicle preparation. The vesicles are washed to remove unbound annexin V and next examined by fluorescence microscopy. Presence of annexin V is detected by green fluorescence, as shown above. What can be deduced from these data?