Module 4 Passive Transport: Diffusion and Osmosis

Which one of the following is the difference between osmosis and diffusion?

Osmosis refers specifically to the movement of water, whereas diffusion refers to the movement of any type of molecules.

Fill in the blank: The driving force of facilitated diffusion is _______.

Concentration gradient

Complete the following sentence: The rate of diffusion of a particular solute is NOT affected by...

Concentration gradients of other solutes.

If you are going to bake potatoes, and your potatoes are soft and dehydrated, they can be soaked in __________ to make them firmer before baking.

a hypotonic solution such as tap water

A human cell placed into a hypertonic solution is likely to...

lose water by osmosis.

Facilitated diffusion is a type of _______.

passive transport

Water molecules passes through specialized channels in membranes in the process of osmosis. Which of the following statements about osmosis are false? A. Water will move across a membrane to a region with less solute. B. The direction of osmosis is temperature dependent. C. If the membrane does not allow solutes to pass, water will be equal on both sides. D. Water will move across a membrane to a region with more solute. E. A higher solute concentration on one side of a membrane indicates a higher water concentration on that side. F. All of the above.

A, B, C and E

A bacterial cell must obtain glucose for its metabolism. If glucose is in higher concentration outside the cell than inside, but the plasma membrane and other surface layers of the cell do not allow glucose to pass through, which is the most likely type of transport for glucose?

Facilitated diffusion via a gated channel

A hospital patient is mistakenly given an IV of pure water instead of a saline solution that is isotonic to blood. The patient's red blood cells will release water to the plasma along its concentration gradient.

False

True or False: A hospital patient is mistakenly given an IV of pure water instead of a saline solution that is isotonic to blood. The patient's red blood cells will transport equal amounts of water across the cell membrane in both directions.

False

True or False: Osmosis and diffusion are different, and only the process of osmosis varies according to the kinds of particles present.

False

True or False: Temperature does NOT affect the rate of diffusion of a particular solute.

False

True or False: There are mechanisms for glucose transport in cells. Researchers place cells in a solution of glucose in which the concentration of glucose is gradually increased in a hypothetical study. At beginning, while the concentration of the glucose solution is increasing, the rate at which glucose enters the cells is also increasing. However, there is no change in the rate, when the glucose concentration of the solution is increased above 10 M. Facilitated diffusion via a channel protein is the likely mechanism for glucose transport in these cells.

False

True or False: There are mechanisms for glucose transport in cells. Researchers place cells in a solution of glucose in which the concentration of glucose is gradually increased in a hypothetical study. At beginning, while the concentration of the glucose solution is increasing, the rate at which glucose enters the cells is also increasing. However, there is no change in the rate, when the glucose concentration of the solution is increased above 10 M. Facilitated diffusion via pinocytosis is the likely mechanism for glucose transport in these cells.

False

True or False There are mechanisms for glucose transport in cells. Researchers place cells in a solution of glucose in which the concentration of glucose is gradually increased in a hypothetical study. At beginning, while the concentration of the glucose solution is increasing, the rate at which glucose enters the cells is also increasing. However, there is no change in the rate, when the glucose concentration of the solution is increased above 10 M. Facilitated diffusion via pinocytosis is the likely mechanism for glucose transport in these cells.

True

True or false: Osmosis is a type of diffusion.

True

Fill in the blank: As an intern in a cell biology lab, you are asked to change the medium in which cells are growing. After doing this, you checked the cells under microscope, however, what you see is not the cells but cell debris. The reason for this is that the cells ______ because the new medium was _______ to the cells.

burst, hypotonic