Plasma membrane in animals is composed mainly of

The correct answer is Lipo-protein molecules

Explanation:

• The plasma membrane, also known as the cell membrane, is a biological membrane that separates the interior of all cells from the external environment.
• It plays a vital role in maintaining the structural integrity of the cell, regulating the movement of substances in and out of the cell, and facilitating communication and signaling between cells.
• The plasma membrane is primarily composed of a lipid bilayer interspersed with proteins.

• S. Jonathan Singer and Garth Nicolson proposed the Fluid Mosaic Model in 1972.
• According to this model, the structure of the plasma membrane is a mosaic and is made up of lipids, proteins, cholesterol, and carbohydrates.
• Lipids are present in the form of two layers known as lipid bilayers with protein embedded in it.
• The major constituent of lipids is phospholipids. Each phospholipid is made up of a hydrophilic head and a hydrophobic tail.
• Two types of proteins present in the plasma membrane are peripheral proteins and integral proteins. Integral proteins are deeply embedded in the membrane as compared to the peripheral proteins.
• Cholesterol helps in retaining the fluidity of the membrane.

Other Options:

• Fat molecules: Although lipids, a category of fats, are a critical component of the plasma membrane. The lipids in the membrane are primarily phospholipids, not simple fats.
• Carbohydrate molecules: Carbohydrates are present in the plasma membrane, but they are not the main structural component. They are attached to lipids (glycolipids) or proteins (glycoproteins) and play a role in cell recognition and signaling.
• Protein molecules: Proteins are a significant component of the plasma membrane, but they are not the sole component. They work in conjunction with lipids to form the lipo-protein structure. Proteins serve various functions, such as acting as channels, carriers, receptors, and enzymes.