Question

What is the difference between outer leaflet and inner leaflet?

A) Outer leaflet faces the extracellular environment, while inner leaflet faces the cytoplasm
B) Outer leaflet is hydrophobic, while inner leaflet is hydrophilic
C) Outer leaflet contains phospholipids, while inner leaflet contains cholesterol
D) Outer leaflet has a higher concentration of proteins than the inner leaflet

Answer 1

The outer leaflet of a cell membrane faces the extracellular space, while the inner leaflet faces the cytoplasm, with both leaflets containing hydrophilic phospholipid heads that are exposed to aqueous environments.

Step-by-step explanation:

The cell membrane is made up of two layers of phospholipids, forming a bilayer. The outer leaflet of the membrane faces the extracellular environment, while the inner leaflet faces the cytoplasm. The heads of phospholipids, which are polar and hydrophilic, face outward towards the water-based intracellular and extracellular fluids, while the hydrophobic fatty acid tails face inward, away from the water.

The difference between the outer leaflet and inner leaflet of a cell membrane is that the outer leaflet faces the extracellular environment, while the inner leaflet faces the cytoplasm. This means that the hydrophilic heads of phospholipids in the outer leaflet are exposed to the extracellular fluid, and the hydrophilic heads in the inner leaflet are exposed to the intracellular fluid. Both leaflets consist of phospholipids and may contain other lipids like cholesterol, and proteins that contribute to the membrane's functionality. The plasma membrane's asymmetry also reflects differences in the composition and function of the lipids and proteins between the two leaflets.