Question

In passive transport, carrier protein is required to facilitate transport of

• A. Neutral solutes
• B. Hydrophobic molecules
• C. Non polar molecules
• D. Polar molecules

Answer 1

The correct option is D Polar molecules

Plasma membrane is made of phospholipids, which allows the movement of neutral solutes. Polar molecules for example water requires carrier proteins as they are attracted towards the phopholipid heads (hydrophilic) of lipid bilayer while are repelled by the fatty acyl tail (hydrophobic) and hence cannot pass through the lipid bilayer that constitutes the plasma membrane.

So, the correct answer is 'Polar molecules'