Which of the following statements regarding animal cell membrane is correct?

The correct answer is They are composed of phospholipids, proteins and cholesterol (lipid).

Key Points

• Animal cell membranes are primarily composed of three major components: phospholipids, proteins, and cholesterol.
• Phospholipids form a bilayer that provides the fundamental structure of the membrane.
• Proteins are embedded within this bilayer and serve various functions such as transport, signal transduction, and acting as enzymes.
• Cholesterol is interspersed within the phospholipid bilayer, providing stability and fluidity to the membrane.
• This structure is often referred to as the fluid mosaic model because of the flexible nature of the lipid bilayer and the mosaic-like distribution of proteins.

 Additional Information

• Phospholipids
  • They have hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails.
  • This dual nature allows them to form bilayers in aqueous environments, which is essential for creating the cell membrane's structure.
• Proteins
  • Integral proteins span the membrane, while peripheral proteins are attached to the exterior or interior surfaces.
  • They play crucial roles in transport, acting as channels or carriers for molecules to enter or exit the cell.
• Cholesterol
  • It helps to modulate the fluidity of the membrane, making it less permeable to very small water-soluble molecules that might otherwise pass through more easily.
  • Cholesterol is particularly important in maintaining the integrity and functionality of the cell membrane under varying temperature conditions.