Students can go through AP State Board 9th Class Biology Notes Chapter 4 Movement of Materials Across the Cell Membrane to understand and remember the concept easily.
AP State Board Syllabus 9th Class Biology Notes Chapter 4 Movement of Materials Across the Cell Membrane
→ Cell performs different functions.
→ Different types of substances like glucose, water, and oxygen are required by the cell to perform functions.
→ Saturated solutions do not dissolve substances further.
→ The cells in the outer layer of Kishmish permit water to pass through.
→ In Greek ‘Osmos’ means pushing.
→ The movement of solvent molecules through a semipermeable membrane in a solution from a low high concentration till the concentration on both sides becomes equal is called ‘Osmosis’.
→ Permeability means allowing substances into the cell through a semipermeable membrane.
→ The plasma membrane is selectively permeable allows entry of certain substances to pass through it
→ The plasma membrane is semipermeable to solvent but prevents the passage of solutes.
→ The process in which water molecules leave the cell is called ‘Exosmosis’.
→ The process in which water molecules enter the cell is called ‘Endosmosis’.
→ Freddie Mercury and David Bowie removed salt from seawater by using a semipermeable membrane by a process called desalination.
→ Reverse osmosis helps in removing salt from seawater.
→ The process by which some materials when kept in a medium like air and water spread equally throughout, is called diffusion.
→ Air freshness, Agarbathi, mosquito repellants work on the principle of diffusion.
→ Thomas Graham measured the rate of diffusion of gases and also studied the diffusion of substances in solutions.
→ Osmosis does not take place in dead cells.
→ Solute: Dissolved substance in a solution.
→ Solvent: A fluid substance that dissolves solid substances.
→ Selectively permeable: Allows entry of certain substances only.
→ Endocytosis: Flexibility of the cell membrane to engulf food and other substances from the external environment. E.g.: Amoeba.
→ Osmosis: The movement of water molecules towards concentrated solutions.
→ Plasmodesmata: The strands of cytoplasm passing through cell walls and connecting the protoplasts of adjacent cells.
→ Permeability: The extent to which molecules of a given kind can pass through a membrane.
→ Semipermeable: Only certain materials are allowed to enter the cell.
→ Circumference: A line that goes around a circle or any other curved shape, the length of this line.
→ Exosmosis: The process in which water molecules leave the cell.
→ Endosmosis: The process in which water molecules enter the cell.
→ Reverse Osmosis: A process used to remove salts from the water.
→ Diffusion: Some materials when kept ¡n a medium like air and water spread equally ¡n that medium.
→ Saturated solution: It is a solution in which solute further can not dissolve.
→ Three fourth of the earth is covered with oceans. Though plenty of water is there, we cannot use it, since it is salty. If we can remove salts from it we can use it. Freddie Mercury and David Bowie removed salt from seawater by using a semi-permeable membrane by a process called desalination. When heavy pressure is applied to a salt solution, which is separated from freshwater with a semi-permeable membrane, the water moves from the salt solution into freshwater leaving the salt behind. This process is known as reverse osmosis. Nowadays domestically used reverse osmosis machines are available in the market, which filters saltwater through three membranes.
→ Thomas Graham, the Scottish physical chemist, worked on the diffusion of gases. Graham measured the rate of diffusion of gases and also studied the diffusion of substances in solutions. He had inferred that a more soluble substance in a medium diffuse faster than a less soluble substance. This is popularly known as ‘Graham’s law’.
→ Thomas Graham:
- Thomas Graham a Scottish physical chemist, worked on the diffusion of gases.
- He also studied the diffusion of substances in solutions.
- Thomas Graham inferred that a more soluble substance in a medium diffuse faster than a less soluble substance.
- This is popularly known as Graham‘s law.