Cell- Fundamental Unit Of Life Class 9 Chapter 5

CELL MEMBRANE OR PLASMA MEMBRANE

• The boundary of each cell which separates the cytoplasm from surroundings
• It is made up of proteins and lipids.
• It is Flexible and can be folded, broken and reunites
• Present in both Animal cell and plant cell
• Plasma membrane is called selectively permeable membrane because it allows the entry and exit of selected material inside and outside the cell.
• It helps in exchange of gases like O₂ (Oxygen), and CO₂ (Carbon Dioxide) by the process of Diffusion.
• It allows movement of water inside and outside the cell by the process of Osmosis.

MOVEMENT OF SUBSTANCES THROUGH PLASMA MEMBRANE

Diffusion- It is the Spontaneous movement of a substance from high concentration region to low concentration region through plasma membrane. Oxygen and Carbon dioxide can move across the Plasma membrane by diffusion process.

Osmosis- The movement of water molecules through plasma membrane from high concentration region to low concentration region is known as Osmosis