The hydrophobic tails of a Phospholipid bilayer are oriented towards the: Extracellular matrix Interior of the plasma membrane Nucleus of the cell Cytoplasm of the cell Extracellular fluid surrounding the cell
The Correct Answer and Explanation is:
Correct Answer: Interior of the plasma membrane
Explanation:
Phospholipids are essential components of the plasma membrane, which forms the outer boundary of cells. Each phospholipid molecule has a hydrophilic head (water-loving) and hydrophobic tails (water-fearing). This structural characteristic influences how phospholipids are arranged in the membrane.
In an aqueous environment such as the interior of a cell (cytoplasm) and the extracellular fluid surrounding the cell, the hydrophilic heads of phospholipids naturally orient themselves towards the water. These water-friendly heads face outward, both toward the cytoplasm and the extracellular fluid. In contrast, the hydrophobic tails, which repel water, orient themselves away from the water.
As a result, the phospholipids form a bilayer in which the hydrophobic tails point inward, facing each other, away from the watery environments on either side of the membrane. This inward orientation creates the interior of the plasma membrane, a stable and selectively permeable barrier that separates the internal cellular environment from the external one.
This arrangement is crucial because it enables the membrane to maintain its integrity and function. The interior hydrophobic region prevents the free passage of water-soluble substances, which allows the cell to control what enters and exits. It also supports the proper function of embedded proteins, receptors, and other membrane components.
The orientation of the hydrophobic tails toward the interior of the plasma membrane is not toward the nucleus specifically, nor exclusively toward the cytoplasm or extracellular fluid. Instead, it is a universal feature of all cell membranes that ensures structural stability and controlled permeability in a watery environment.
