Question

Fluidity of cell membranes in cold weather is maintained by

• A. Increasing number of phospholipids with unsaturated hydrocarbon tails
• B. Increasing the proportion of integral proteins
• C. Increasing concentration of cholesterol in membrane
• D. Increasing the number of phospholipids with saturated hydrocarbon tails

Answer 1

Answer: (A)

Increasing number of phospholipids with unsaturated hydrocarbon tails

• The unsaturated fatty acids (or hydrocarbon tails) present in the cell membrane gets compressed in cold conditions which pushes the adjacent phospholipid molecules away and thus, it helps to maintain fluidity in the membrane.
  
• So, the correct answer is 'Increasing number of phospholipids with unsaturated hydrocarbon tails'.