Structure of cell details_07-03(1)_Full HD
- 5 years ago
The cell is bound by the living outer boundary called
lasma membrane. The major chemical constituents
f plasma membrane are the proteins, lipids, and
arbohydrates. According to the unit membrane
nodel of Robertson, the plasma membrane
f two layers of molecules, each about 20 A thick,
vith a central layer of about 35 A thick, forming a
otal thickness of 75 Ä. According to the Fluid Mosaic
nodel of Singer and Nicholson, there is a double laye
of lipid molecules (phospholipids) with globular
protein molecules and sterols which are arranged
lifferently in different parts of the plasma
nembrane. The plasma membrane is 'selectively
ermeable' and regulates the flow of materials in and
ut of the cell. The vital functions of plasma
nembrane are protection and support, passive and
ctive transport of molecules, phagocytosis (or cell
eating), and pinocytosis (cell drinking).
lasma membrane. The major chemical constituents
f plasma membrane are the proteins, lipids, and
arbohydrates. According to the unit membrane
nodel of Robertson, the plasma membrane
f two layers of molecules, each about 20 A thick,
vith a central layer of about 35 A thick, forming a
otal thickness of 75 Ä. According to the Fluid Mosaic
nodel of Singer and Nicholson, there is a double laye
of lipid molecules (phospholipids) with globular
protein molecules and sterols which are arranged
lifferently in different parts of the plasma
nembrane. The plasma membrane is 'selectively
ermeable' and regulates the flow of materials in and
ut of the cell. The vital functions of plasma
nembrane are protection and support, passive and
ctive transport of molecules, phagocytosis (or cell
eating), and pinocytosis (cell drinking).