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Functions of Cell Membrane

Functions of Cell Membrane
1. Mechanical Support
It provides mechanical support to the protoplasm.
2. External Form
It provides external form to cell.
3. Transportation
Transport of materials, which is vital for cell, occurs through cell membrane. It offers a barrier between the cell contents and their environment allowing only selective substances to pass through it. Thus it is also known as differentially permeable or selectively permeable membrane.
4. Regulation of Materials
It regulates the flow of materials and ions to maintain definite gradient across it.
  • The substances, which are lipid soluble, cross it more easily.
  • Many small gas molecules, water, glucose etc being neutral can easily cross.
  • Ions, beings charged particles have some difficulty in crossing.
5. Active Transport
Many substances, which are not needed, enter the cell by passive transport. These are then pushed out by active transport. The energy for this transport is provided by ATP.
6. Endocytosis
In many animal cells, the cell membrane helps to take in materials by infoldings in the form of vacuoles. This type of intake is termed as endocytosis. It may be;
  • Phagocytosis – ingestion of solid material.
  • Pinocytosis – ingestion of liquid material.
7. Conduction
In neuron (nerve cells), the cell membrane transmits nerve impulse from one part of the body to the other to keep coordination.

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