Question

The process of osmosis involves (a) Movement of solute through semi-permeable membrane (b) Movement of solvent through a semi-permeable membrane (c) Movement of solution through a semi-permeable membrane (d) None of these

Short answer

The correct answer is (b) Movement of solvent through a semi-permeable membrane.

Step-by-step solution

Understanding osmosis

Osmosis is a process that facilitates the movement of a solvent from an area of low solute concentration to one of high solute concentration. This movement occurs across a semi-permeable membrane, which only allows certain molecules to pass through.

Analyzing the answer options

Looking at the options provided in the question: \nOption (a) suggests that solutes move across the semi-permeable membrane. However, the osmotic process primarily focuses on the movement of solvent particles, not solute. \nOption (b) suggests that the solvent moves across the semi-permeable membrane, which aligns with the definition of osmosis. \nOption (c) suggests that the solution moves through the semi-permeable membrane, but the solution is made up of both solute and solvent elements. While some solvents can move across the membrane, solute particles, especially larger ones, often cannot. \nOption (d) suggests none of the above options, so it would be incorrect if one of the above options is correct.

Selecting the right answer

Based on the definition of osmosis, option (b), which states the 'Movement of solvent through a semi-permeable membrane,' is the most accurate description of osmosis. So, option (b) is the right answer.

Key concepts

Solvent Movement

In the context of osmosis, solvent movement is the key process. Osmosis involves the passage of the solvent, usually water, from an area where it is highly concentrated to an area where its concentration is lower. This happens in order to balance solute concentrations across what we call a semi-permeable membrane.

Think of solvent movement as water in a crowded room trying to move to a less crowded room, through a doorway, to balance the crowd in both rooms. The importance of solvent movement in osmosis cannot be overstated because it is the mechanism that facilitates vital biological processes.

• Solvent molecules move down their concentration gradient.
• The process does not require energy, making it a passive transport.

Whether it's the cells in our body or plants absorbing water from the soil, osmosis and solvent movement play a critical role in maintaining equilibrium and stability.

Semi-permeable Membrane

A semi-permeable membrane is crucial to the process of osmosis. It acts as a selective barrier that allows only specific types of molecules to pass through. Typically, this means the membrane will allow solvent molecules like water to move freely, but will restrict certain solute particles, especially larger ones.

Imagine a fine mesh screen door that lets air in but keeps insects out—that's similar to how a semi-permeable membrane functions.

• Semi-permeable membranes consist of thin, specialized structures.
• They are essential in separating different solutions and their components.

In cells, this type of membrane is what separates the interior of a cell from its surrounding environment, maintaining balance, and allowing communication between the two.

Solute Concentration

Solute concentration refers to how much solute exists within a given volume of solvent. In osmosis, it's the difference in solute concentration across a semi-permeable membrane that drives the movement of solvent. Osmosis will continue until solute concentrations are equalized on both sides of the membrane.

Consider solute concentration as the flavor of a soup—too light on one side might cause the flavor (or solute) from another side to diffuse into it until both sides taste the same.

• Solute concentration dictates the direction of osmotic flow.
• Higher solute concentration areas will "pull" solvent molecules towards them.

By understanding solute concentration, we can predict how and why water moves within biological systems, impacting processes like nutrient absorption and waste elimination.