Final answer:
Cholesterol embedded within the phospholipid bilayer of the plasma membrane provides structural strength by contributing flexibility and maintaining integrity.
Step-by-step explanation:
The structural strength of the plasma membrane is attributed to cholesterol, which is embedded within the phospholipid bilayer.
Cholesterol's role in the plasma membrane is to provide flexibility and maintain the membrane's integrity at various temperatures, thus contributing to its structural strength.
Phospholipids are important components of the plasma membrane, forming the bilayer with hydrophilic heads facing the aqueous environment and hydrophobic tails facing each other inwards.
These lipids allow for the fluid mosaic nature of the membrane, while the presence of double bonds in the fatty acid tails further contributes to the fluidity.
Additionally, carbohydrates commonly function in cell recognition and adhesion, but are not directly involved in the membrane's structural integrity.