Water Potential

Which of the following statements is true?

• Water is transported actively against a concentration gradient.

• Water flows into the direction of the lowest water potential.

• Active transport is ATP-independent.

• Osmosis requires impermeable membranes.

The soil surrounding the roots of a plant has a water potential of -15 bars. The leaves of the plant have a water potential of -18 bars.
What will happen?

• Water will leave the plant and the plant will wilt.
• Water will move from the roots to the leaves of the plant.
• Nothing - these solutions are isotonic.
• IDK - What is a bar????

A saltwater fish is accidentally placed in a freshwater aquarium in a few short hours it sadly died. Which explains why this occurred?

• The cells of the fish body were dehydrated by the quick loss of water. 
• The cells of the fish quickly absorbed massive amounts of water and it ended up killing the fish.  
  
• The fish hated the new decor in the freshwater tank. 
• It was just its time. 

Pure water has a water potential of ___.

• 1
• 0
• -1
• 100

A sucrose solution in a beaker has a solute potential of -4 bars.  A cell with a solute potential of -2 bars is placed in the beaker.  What will be the direction for the net movement of water?

• into the cell
• out of the cell
• there will be no net movement

Assume that the “cell” below is permeable to sucrose, glucose, and water but impermeable to starch. Which of the following statements is correct?

• (A) Starch will diffuse into the cell.

• (B) Starch will diffuse out of the cell.

• (C) There will be no net movement of glucose

• (D) Glucose will diffuse into the cell

• (E) Sucrose will diffuse into the cell

Assume the “cell” is permeable to water only. If the cell contains a 0.3 M solution of glucose and the environment contians a 0.1 M solution of glucose, which of the following statements would be true?

• (A) The cell will decrease in volume.

• (B) Glucose will enter the “cell.”

• (C) Pinocytosis will occur.

• (D) There would be a net movement of water into the “cell.”

• (E) There would be no net movement of water.

If a cell with a solute potential of - 0.2 MPa and a pressure potential of 0.4 MPa is placed in a chamber filled with pure water that is pressurized with 0.5 MPa, what will happen?

• A)Water will flow out of the cell.

• B)Water will flow into the cell.

• C)The cell will be crushed.

• D)The cell will explode.

You place a piece of potato weighing 0.3 gram with a water potential of 1 MPa in a beaker of Pepsi. After 10 minutes, you remove the potato piece, and it now weighs 0.25 gram. You conclude that

• a). Pepsi Cola has a water potential greater than 1 MPa.

• b). Pepsi Cola has a water potential of 0 MPa.

• c). Pepsi Cola has a water potential less than 1 MPa.

• d). Pepsi Cola does not have turgor pressure, and so you cannot conclude anything about its water potential.

An animal cell with a solute potential of -2.0 bar is placed into a solution with a solute potential of -1.5 bar. What is the net direction of water?

• a. Into the cell

• b. Out of the cell

• c. The cell is at equilibrium.

• d. Equal amounts of water move into and out of the cell.