Cell Membrane Properties: Identifying the False Statement

The question asks to identify the statement that is incorrect regarding the cell membrane. Let's analyze each option:

• Statement 1: Phospholipid is an amphipathic molecule

  This statement is true. Amphipathic molecules have both hydrophilic (water-loving) and hydrophobic (water-fearing) parts.

• Statement 2: Phospholipid has both a hydrophilic region and a hydrophobic region

  This statement is also true. The phosphate head of a phospholipid is hydrophilic, while the fatty acid tails are hydrophobic. This is the basis of the cell membrane's structure.

• Statement 3: Membrane proteins can reside in phospholipid bilayer with their hydrophilic regions protruding

  This statement is true. Many membrane proteins are partially or fully embedded in the bilayer. Their hydrophilic parts often interact with the aqueous environment inside and outside the cell, while hydrophobic parts interact with the lipid tails.

• Statement 4: Carbohydrates are totally absent in the cell membrane

  This statement is false. Carbohydrates are typically found on the outer surface of the plasma membrane, forming a layer called the glycocalyx. They are usually attached to proteins (forming glycoproteins) or lipids (forming glycolipids).

Therefore, the statement that is not true for the cell membrane is that carbohydrates are totally absent.