The correct answer is- proteins embedded into two layers of phospholipids
Explanation:
The plasma membrane is a mosaic of many components like phospholipids, proteins, carbohydrates, and cholesterol. This mosaic nature of cell membrane gives a fluid character to the membrane.
So due to this fluidity, the proteins present in the membrane can do movements like flip flop which helps in the movement of molecules across the membrane.
These proteins are called transporter which gives the property of selective permeability to the cell membrane because they bind specifically to some molecules and allow them to cross the cell membrane.
Cocaine appears to produce its effects largely by increasing the supply of the neurotransmitter dopamine at key neurons throughout the brain. The missing word is dopamine. I hope this is the answer that you were looking for.
