Which supports the idea that a membrane is asymmetric?
a. the ratio of the area of lipids extracted from red cell membranes to the area of the membranes was 2:1
b. particles were seen in freeze-fractured samples of membranes
c. addition of certain antibodies to cells caused patching of the antigens.
d. Certain proteins can be labeled from either side of a membrane
e. Certain proteins can be labeled from only one side of a membrane.