A) On the \[{{\operatorname{PO}}_{4}}\] groups of cell membrane facing extracellular fluid.
B) On the \[{{\operatorname{PO}}_{4}}\] groups of cell membrane facing cytosol.
C) Only on inner lumen of ER.
D) On both inner and outer laminae of ER.
Correct Answer: A
Solution :
The phospholipid molecule generally consists of two hydrophobic fatty acid "tails" and a hydrophilic "head" consisting of a phosphate group. In ER, the hydrophilic head is facing the lumen. When ER buds off vesicles, labelled \[P{{O}_{4}}\] group will be facing the lumen of the vesicle. When this vesicle fuses with plasma membrane, its surface facing lumen will face the extracellular fluid. So, phosphate group also face the extracellular fluid.You need to login to perform this action.
You will be redirected in
3 sec