Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct?

Question: Which of the following statements about the role of phospholipids in forming membranes is correct? (Concept 7.1E-Book) [Hint]

Phospholipids are completely insoluble in water.

Phospholipids form a single sheet in water.

Phospholipids form a structure in which the hydrophobic portion faces outward.

Phospholipids form a selectively permeable structure.

They are triacylglycerols, which are commonly available in foods.

Answer: Phospholipids form a selectively permeable structure.

Explanation:

Phospholipid bilayer of the plasma membrane are arrange in bilayer with the polar head group oriented towards the extracellular side and the cytoplasmic side with a hydrophobic core.

Phospholipids form a highly selectively permeable structure. It regulates the entry and exit of compounds. Only lipid soluble compound are permeable across the cell membrane, while water soluble compounds are generally impermeable and require carrier mediated transport.

An important function of the membrane is to withhold unwanted molecules, while permitting entry of molecules necessary for cellular metabolism.