Which statement correctly describes the polarity of phospholipid components?

Which statement correctly describes the polarity of phospholipid components?

• A. Polar; nonpolar
• B. Nonpolar; polar
• C. Polar; polar
• D. Nonpolar; nonpolar

Answer: (A)

Phospholipids are amphipathic: one part is polar and attracted to water, while another part is nonpolar and repels water. The polar portion is the head, which contains a phosphate group and is hydrophilic, so it interacts with the aqueous environment. The nonpolar portion is the fatty acid tails, which are long hydrocarbon chains that do not interact well with water and are hydrophobic. So, the correct description is that the head is polar and the tails are nonpolar. This polarity pattern is what drives the formation of cell membranes, with heads facing the watery surroundings and tails tucked away from water, creating a bilayer. The other possible descriptions would imply both parts share the same polarity, which doesn’t fit how phospholipids behave in water.

Phospholipids are amphipathic: one part is polar and attracted to water, while another part is nonpolar and repels water. The polar portion is the head, which contains a phosphate group and is hydrophilic, so it interacts with the aqueous environment. The nonpolar portion is the fatty acid tails, which are long hydrocarbon chains that do not interact well with water and are hydrophobic.

So, the correct description is that the head is polar and the tails are nonpolar. This polarity pattern is what drives the formation of cell membranes, with heads facing the watery surroundings and tails tucked away from water, creating a bilayer. The other possible descriptions would imply both parts share the same polarity, which doesn’t fit how phospholipids behave in water.