Osmosis 5.4

What happens to a plant cell that is in an isotonic solution?

It turns flaccid (limp)

What is the control of water balance called?

osmoregulation

Hypotonic

a solution with a solute concentration lower than that of the cell.

Why is water balance different for the cells of plants, prokaryotes, and fungi?

because of the cell wall

Isotonic

cells volume remains constant as solute concentration is equal in the cell and in the solution.

Do the walled cells of bacteria and fungi also plasmolyse in a hypertonic solution?

YES!!!!

Hypertonic

A solution with a higher solute concentration.

Indicate the direction of net water movement between two solutions - a .5% sucrose solution and 2% sucrose solution - separated by a membrane not permeable to sucrose.

From the .5% sucrose solution (lower solute concentration) to the 2% sucrose solution (higher solute concentration.

What does the tonicity of a solution depend on?

It depends on its concentration of solutes that cannot cross the plasma membrane relative to the concentration of solutes inside the cell.

What is the diffusion of water across a selectively permeable membrane called?

Osmosis

What happens at the molecular level of osmosis?

Polar water molecules cluster around hydrophilic (water-loving) solute molecules. The effect is that on the right side, there are fewer water molecules available to cross the membrane. The less concentrated solution on the left, with fewer solute molecules free to move. There is a net movement of water down its own concentration gradient, from the solution with more free water molecules (and lower solute concentration) to that with fewer free water molecules (and higher solute concentration)

What happens when an animals cell is placed in a Hypotonic solution?

The cell gains water, swells, and may burst (lyse) like an overfilled balloon.

What happens when an animal cell is placed in a Hypertonic solution?

The cell shrivels and can die from water loss.

What happens when an animal cell is placed in an ISOTONIC solution?

The cell's volume remains constant as the solute concentrate of a cell and its isotonic environment are essentially equal, and the cell gains water at the same rate that it loses it.

Why are meats often stored with salt?

The cells of food-spoiling bacteria and fungi become plasmolyzed and eventually die.

What happens to a plant cell when it is in a hypertonic solution.

The plant cell shrivels as it loses water and its plasma membrane pulls away from the cell wall. This process is called plasmolysis and can be lethal to the plant cell and the plant.

What happens to a plant cell that is in a hypotonic solution?

The plant cells is turgid (firm), which is a healthy state for most plant cells. To become turgid, a plant cell needs a net flow of water; Although the somewhat elastic cell wall expands a bit, the pressure it exerts prevents the cell from taking in too much water and bursting, as an animal cell would in a hypotonic environment. Plants that are not woody, such as most houseplants, depend on their turgid cells for mechanical support.

What is the ability of a surrounding solution to cause a cell to gain or lose water.

Tonicity