LIFE SCIENCE

Detailed explanation-1: –The hydrophilic heads of phospholipids face the aqueous environment inside and outside the cell.-This allows the membrane to conserve internal fluids and maintain a stable environment for the cell. Therefore, the answer is B) Phospholipids.

Detailed explanation-2: -Because their fatty acid tails are poorly soluble in water, phospholipids spontaneously form bilayers in aqueous solutions, with the hydrophobic tails buried in the interior of the membrane and the polar head groups exposed on both sides, in contact with water (Figure 2.45).

Detailed explanation-3: -Phospholipids are major membrane lipids that consist of lipid bilayers. This basic cellular structure acts as a barrier to protect the cell against various environmental insults and more importantly, enables multiple cellular processes to occur in subcellular compartments.

Detailed explanation-4: -The cell membrane is made of two layers of phospholipids arranged like an ice cream sandwich. The phospholipids along with cholesterol keep the membrane fluid and allow for the passage of materials into and out of the cell.

Detailed explanation-5: -Cholesterol stabilizes the cell membrane by forming interactions with the phospholipid tails and heads. This makes their structure more rigid and helps provide stability.