Which of the following statement is correct about diffusion and osmosis

Which of the following statement is correct about diffusion?

• A. it involves movement of water molecules only
• B. Molecules move from a region of higher concentration to a region of lower concentration
• C. differentially permeable membrane must be present for diffusion to occur
• D. It involves when a solute can no longer dissolve in a solvent of only solute molecules into the Bowman's capsule
• E. It occurs when a solute can no longer dissolve in a solvent

Correct Answer: Option B

Explanation

Quick Questions

• 

  Figure \(\PageIndex{1}\). (CC BY-NC-SA)

  Osmosis

  Osmosis is a specific type of diffusion; it is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. 

  Semi-permeable membranes are very thin layers of material which allow some things to pass through them, but prevent other things from passing through. Cell membranes are an example of semi-permeable membranes. Cell membranes allow small molecules such as oxygen, water carbon dioxide and glucose to pass through, but do not allow larger molecules like sucrose, proteins and starch to enter the cell directly.

  

  Figure \(\PageIndex{2}\). (CC BY-NC-SA)

  Example: If there was a semi-permeable membrane with more water molecules on one side as there were on the other, water molecules would flow from the side with a high concentration of water to the side with the lower concentration of water. This would continue until the concentration of water on both sides of the membrane were equal (dynamic equilibrium is established).

  

  Figure \(\PageIndex{3}\). (CC BY-NC-SA)

  Osmotic Pressure
  Adding sugars to water will result in a decrease in the water concentration because the sugar molecules displace the water molecules. 

  

  Figure \(\PageIndex{4}\). osmotic pressure (CC BY-NC-SA; LadyOfHats)

  If the two containers are connected, but separated by a semi-permeable membrane, water molecules would flow from the area of high water concentration (the solution that does not contain any sugar) to the area of lower water concentration (the solution that contains sugar). 

  

  Figure \(\PageIndex{5}\). osmotic pressure (CC BY-NC-SA; LadyOfHats)

  This movement of water would continue until the water concentration on both sides of the membrane is equal, and will result in a change in volume of the two sides. The side that contains sugar will end up with a larger volume.

  

  Figure \(\PageIndex{6}\). osmotic pressure (CC BY-NC-SA; LadyOfHats)

  Water solutions are very important in biology. When water is mixed with other molecules this mixture is called a solution. Water is the solvent and the dissolved substance is the solute. A solution is characterized by the solute. For example, water and sugar would be characterized as a sugar solution.

  The classic example used to demonstrate osmosis and osmotic pressure is to immerse red blood cells into sugar solutions of various concentrations. There are three possible relationships that cells can encounter when placed into a sugar solution.

  1. The concentration of solute in the solution can be equal to the concentration of solute in cells. In this situation the cell is in an isotonic solution (iso = equal or the same as normal). A red blood cell will retain its normal shape in this environment as the amount of water entering the cell is the same as the amount leaving the cell.

  2. The concentration of solute in the solution can be greater than the concentration of solute in the cells. This cell is described as being in a hypertonic solution (hyper = greater than normal). In this situation, a red blood will appear to shrink as the water flows out of the cell and into the surrounding environment.

  3. The concentration of solute in the solution can be less than the concentration of solute in the cells. This cell is in a hypotonic solution (hypo = less than normal). A red blood cell in this environment will become visibly swollen and potentially rupture as water rushes into the cell.

  

  Figure \(\PageIndex{4}\). (CC BY-NC-SA)

  

  Figure \(\PageIndex{4}\). (CC BY-NC-SA)

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  This page titled Diffusion and Osmosis is shared under a CC BY-NC-SA license and was authored, remixed, and/or curated by Katherine Harris.

  Which statement is correct for both diffusion and osmosis?

  Both osmosis and diffusion equalize the concentration of two solutions. Both diffusion and osmosis are passive transport processes, which means they do not require any input of extra energy to occur.

  Which of the following statement is correct about the diffusion?

  Detailed Solution The correct answer is 3 i.e. The rate of diffusion increases on increasing with the temperature of the diffusing substance. Details about the process of Diffusion: The spreading out and mixing of a substance with another substance due to the motion of its particles is called diffusion.

  Which one of the following statements about osmosis is correct?

  In this process, the water molecule moves from a region of higher solvent concentration to the region of lower solvent concentration. The energy which drives this process is called osmotic pressure. Osmosis is of great importance in biological processes in plants and animals both. Thus, the correct answer is option D.

  Which statement best describes how osmosis and diffusion are similar?

  Diffusion is the movement of particles from high to low concentration and osmosis is specifically the movement of water molecules from a high to low concentration. Diffusion and osmosis are the same thing.