Cell Membrane/Plasmalemma/Plasmamembrane
Plasmalemma is outer living, dynamic, semipermeable boundary of cells or a
cell compartments (all the cell organelles).
History of concept Building
1. Ernst Overton-Zurich University-1890
Mr. Overton performed a very simple experiment with root hair and lipid
soluble pigments. Root hair dipped in lipid soluble pigment takes stain
faster than the aqueous pigments.
Inference : The lipid soluble pigments can easily solubilize the lipid
component of the cell membrane thus cell membrane composed of lipid
component.
2. E. Groter and F. Grendel Dutch Scientist-1925
They measured the total surface area of RBC ghost and after that
they isolated the entire lipid content on the water film and measure the
surface area.
Surface area of RBC ghost/ a layer of lipid on water film ~ 1:2 or 1: 1.8
Inference the cell membrane composed of lipid bilayer.
? Lipid bilayer is impermeable to the polar solute then how the polar
molecules move across the cell membrane?
3. Davson and James Danielli-1935
Proteins form a layer on the lipid bilayer and across the cell membrane.
The channels across the cell membrane allow the movement of polar
molecules across the cell membrane.
Fluid Mosaic Model of Cell Membrane-Central dogma of Cell
membrane :(Jonathan Singer and Garth Nicholson-1960-72)
1. Lipid bilayer build the core of the cell membrane and lipid molecules can
freely move within one of the lipid bilayer.
2. Proteins are associated on either side of lipid bilayer and across the
lipid bilayer.
The Fluid mosaic model presents cell membrane as dynamic structure in
which components are mobile and capable of self reunion to engage in
various type of weak interactions.
The Chemical composition of cell membrane/ The Structural
components of cell membrane:
Two major components of cell membrane are lipids and proteins.
Lipid Component of cell Membrane:
Plasmalemma is outer living, dynamic, semipermeable boundary of cells or a
cell compartments (all the cell organelles).
History of concept Building
1. Ernst Overton-Zurich University-1890
Mr. Overton performed a very simple experiment with root hair and lipid
soluble pigments. Root hair dipped in lipid soluble pigment takes stain
faster than the aqueous pigments.
Inference : The lipid soluble pigments can easily solubilize the lipid
component of the cell membrane thus cell membrane composed of lipid
component.
2. E. Groter and F. Grendel Dutch Scientist-1925
They measured the total surface area of RBC ghost and after that
they isolated the entire lipid content on the water film and measure the
surface area.
Surface area of RBC ghost/ a layer of lipid on water film ~ 1:2 or 1: 1.8
Inference the cell membrane composed of lipid bilayer.
? Lipid bilayer is impermeable to the polar solute then how the polar
molecules move across the cell membrane?
3. Davson and James Danielli-1935
Proteins form a layer on the lipid bilayer and across the cell membrane.
The channels across the cell membrane allow the movement of polar
molecules across the cell membrane.
Fluid Mosaic Model of Cell Membrane-Central dogma of Cell
membrane :(Jonathan Singer and Garth Nicholson-1960-72)
1. Lipid bilayer build the core of the cell membrane and lipid molecules can
freely move within one of the lipid bilayer.
2. Proteins are associated on either side of lipid bilayer and across the
lipid bilayer.
The Fluid mosaic model presents cell membrane as dynamic structure in
which components are mobile and capable of self reunion to engage in
various type of weak interactions.
The Chemical composition of cell membrane/ The Structural
components of cell membrane:
Two major components of cell membrane are lipids and proteins.
Lipid Component of cell Membrane:
