Which of the following best explains why phospholipids are important in biological systems?

• A. Phospholipids can be stored in adipose tissue for energy storage.
• B. Phospholipids are amphipathic, allowing them to form membranes & be used as emulsifiers.
• C. Phospholipids are entirely hydrophobic, meaning they can protect cell membranes.
• D. Phospholipids are precursors to vitamin D & sex hormones.

Answer: (B)

Verified step by step guidance

1. Understand the structure of phospholipids: Phospholipids consist of a hydrophilic (water-attracting) head and hydrophobic (water-repelling) tails, making them amphipathic molecules.
2. Learn the significance of amphipathic properties: Amphipathic molecules can arrange themselves into bilayers, with hydrophobic tails facing inward and hydrophilic heads facing outward, forming the basis of cell membranes.
3. Explore the role of phospholipids in biological systems: Their ability to form bilayers is crucial for creating selective barriers that regulate the movement of substances in and out of cells.
4. Understand their function as emulsifiers: Phospholipids can stabilize mixtures of water and fat due to their amphipathic nature, which is important in digestion and food processing.
5. Clarify misconceptions: Phospholipids are not entirely hydrophobic, nor are they precursors to vitamin D or sex hormones. Their primary role is forming membranes and acting as emulsifiers.