● The detailed `color{violet}("structure of the membrane")` was studied only after the advent of the `color{violet}("electron microscope")` in the 1950s.
● Meanwhile, chemical studies on the `color{violet}("cell membrane,")` especially in `color{brown}("human red blood cells")` (RBCs), enabled
the scientists to deduce the possible structure of `color{violet}("plasma membrane.")`
● These studies showed that the `color{violet}("cell membrane")` is composed of lipids that are arranged in a `color{brown}("bilayer.")`
● Also, the `color{violet}("lipids")` are arranged within the membrane with the polar head towards the outer sides and the
`color{violet}("hydrophobic tails")` towards the inner part.
● This ensures that the `color{violet}("nonpolar tail")` of `color{violet}("saturated hydrocarbons")` is protected from the aqueous environment.
● The lipid component of the membrane mainly consists of `color{brown}("phosphoglycerides.")`
● Later, `color{violet}("biochemical investigation")` clearly revealed that the cell membranes also possess `color{violet}("protein and carbohydrate. ")`
● The `color{violet}("ratio of protein")` and `color{violet}("lipid varies")` considerably in different cell types.
● In human beings, the `color{brown}("membrane of the erythrocyte")` has approximately 52 per cent protein and 40 per cent lipids.
● Depending on the ease of extraction, `color{violet}("membrane proteins")` can be classified as `color{brown}("integral or peripheral.")`
● `color{violet}("Peripheral proteins lie")` on the surface of membrane while the integral proteins are partially or totally buried in the membrane.
● An improved model of the `color{violet}("structure of cell membrane ")` was proposed by `color{brown}("Singer and Nicolson (1972)")` widely accepted as `color{brown}("fluid mosaic model")`
● According to this, the `color{brown}("quasi-fluid nature")` of lipid enables lateral movement of `color{violet}("proteins")` within the overall `color{violet}("bilayer.")`
● This ability to move within the membrane is measured as its `color{brown}("fluidity.")`
● The `color{violet}("fluid nature")` of the membrane is also important from the point of view of functions like `color{violet}("cell growth,")` formation of intercellular junctions, secretion, endocytosis, cell division etc.
● The detailed `color{violet}("structure of the membrane")` was studied only after the advent of the `color{violet}("electron microscope")` in the 1950s.
● Meanwhile, chemical studies on the `color{violet}("cell membrane,")` especially in `color{brown}("human red blood cells")` (RBCs), enabled
the scientists to deduce the possible structure of `color{violet}("plasma membrane.")`
● These studies showed that the `color{violet}("cell membrane")` is composed of lipids that are arranged in a `color{brown}("bilayer.")`
● Also, the `color{violet}("lipids")` are arranged within the membrane with the polar head towards the outer sides and the
`color{violet}("hydrophobic tails")` towards the inner part.
● This ensures that the `color{violet}("nonpolar tail")` of `color{violet}("saturated hydrocarbons")` is protected from the aqueous environment.
● The lipid component of the membrane mainly consists of `color{brown}("phosphoglycerides.")`
● Later, `color{violet}("biochemical investigation")` clearly revealed that the cell membranes also possess `color{violet}("protein and carbohydrate. ")`
● The `color{violet}("ratio of protein")` and `color{violet}("lipid varies")` considerably in different cell types.
● In human beings, the `color{brown}("membrane of the erythrocyte")` has approximately 52 per cent protein and 40 per cent lipids.
● Depending on the ease of extraction, `color{violet}("membrane proteins")` can be classified as `color{brown}("integral or peripheral.")`
● `color{violet}("Peripheral proteins lie")` on the surface of membrane while the integral proteins are partially or totally buried in the membrane.
● An improved model of the `color{violet}("structure of cell membrane ")` was proposed by `color{brown}("Singer and Nicolson (1972)")` widely accepted as `color{brown}("fluid mosaic model")`
● According to this, the `color{brown}("quasi-fluid nature")` of lipid enables lateral movement of `color{violet}("proteins")` within the overall `color{violet}("bilayer.")`
● This ability to move within the membrane is measured as its `color{brown}("fluidity.")`
● The `color{violet}("fluid nature")` of the membrane is also important from the point of view of functions like `color{violet}("cell growth,")` formation of intercellular junctions, secretion, endocytosis, cell division etc.