Give the biochemical composition of the plasma membrane. How are lipid molecules arranged in the membrane?

(N/A) The biochemical composition of the plasma membrane includes lipids,proteins,and carbohydrates.
$1$. Lipids: The lipid component mainly consists of phosphoglycerides. These lipid molecules are arranged within the membrane in a bilayer,with the polar hydrophilic heads facing the outer sides (aqueous environment) and the non-polar hydrophobic tails facing the inner part. This arrangement protects the non-polar tails of saturated hydrocarbons from the aqueous environment.
$2$. Proteins: Depending on the ease of extraction,membrane proteins are classified as integral or peripheral. Peripheral proteins lie on the surface of the membrane,while integral proteins are partially or totally buried in the membrane.
$3$. Carbohydrates: These are also present in the membrane,often attached to proteins (glycoproteins) or lipids (glycolipids).
In human erythrocytes,the membrane composition is approximately $52\%$ protein and $40\%$ lipids. According to the fluid mosaic model proposed by Singer and Nicolson $(1972)$,the quasi-fluid nature of lipids enables the lateral movement of proteins within the overall bilayer,which is referred to as membrane fluidity.