Name: Facilitated Diffusion: Transport in Plants
Uploaded: 2019-07-19
Duration: 18 min 2 s
Description: Facilitated diffusion occurs when important molecules pass through the membranes via special holes called channels. Watch the video to learn more.

Question

Demonstrate osmosis by means of an experiment.

Accepted Answer

The movement of solute molecules from a region of their higher concentration to the lower concentration separated by a semi-permeable membrane is called osmosis. The molecules of the water inside the compartment or cell create a pressure known as hydrostatic pressure. The hydrostatic pressure which develops during osmosis is known as osmotic pressure. If two solutions of different concentrations are separated by a semi-permeable membrane, then the solvent molecules from the less concentrated solution (which contains more solvent and less solute) move through the membrane to the more concentrated one (which contains less solvent but more solute). During such movement, the fluid level gradually rises in the compartment containing the more concentrated solution, and a position of equilibrium is ultimately reached when the hydrostatic pressure prevents further entry of solvent into this compartment.

A cell contains a variety of solutes. For instance, the mammalian erythrocytes contain the ions like K⁺, ca⁺⁺, PO^4-dissolved haemoglobin, and many other organic substances.

The concentration of intracellular fluid of mammalian erythrocytes is 0·9 gm %. If some human erythrocytes are placed in a 0·9% solution of sodium chloride i.e., isotonic, no structural changes take place.

When the solution is placed in 1% solution, the erythrocytes shrink due to excessive exosmosis.

Demonstrate osmosis by means of an experiment.

Important Questions on Movement of Water, Food, Nutrition and Gases

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