Which molecule makes up the cell membrane and has a phosphate head and two fatty acid tails?

Which molecule makes up the cell membrane and has a phosphate head and two fatty acid tails?

• A. Phospholipid
• B. Protein
• C. Carbohydrate
• D. Nucleic Acid

Answer: (A)

Cell membranes are built from phospholipids, molecules with a hydrophilic phosphate-containing head and hydrophobic fatty acid tails. In water they arrange into a bilayer with heads facing outward and tails tucked inward, forming a semi-permeable barrier. The structure described—one phosphate group head and two fatty acid tails on a glycerol backbone—fits a phospholipid exactly. Other cellular components like proteins, carbohydrates, and nucleic acids are essential in the membrane system, but they don’t match this lipid with a phosphate head and two tails that forms the bilayer.

Cell membranes are built from phospholipids, molecules with a hydrophilic phosphate-containing head and hydrophobic fatty acid tails. In water they arrange into a bilayer with heads facing outward and tails tucked inward, forming a semi-permeable barrier. The structure described—one phosphate group head and two fatty acid tails on a glycerol backbone—fits a phospholipid exactly. Other cellular components like proteins, carbohydrates, and nucleic acids are essential in the membrane system, but they don’t match this lipid with a phosphate head and two tails that forms the bilayer.