According to the material, which of the following is listed as a polar phospholipid?

• A. P-choline
• B. P-serine
• C. P-ethanolamine
• D. P-inositol

Answer: (A)

Phospholipids have a hydrophobic tail and a polar head group, and the polarity is dictated by the head group’s charge and hydrophilicity. Phosphatidylcholine carries a choline head group with a quaternary ammonium, which is permanently positively charged. This creates a strongly polar, zwitterionic head once balanced with the negative phosphate, giving phosphatidylcholine a pronounced polar character compared with the others. The material highlights this head-group charge as the reason it’s listed as a polar phospholipid. The other head groups (serine, ethanolamine, inositol) are also polar, but the distinctive, firmly charged choline head is what makes this lipid stand out as polar in many classifications.