Water Potential (D2.3.1 - D2.3.11) IB Biology HL

Flashcards about Water Potential, Osmosis, Tonicity, and Osmoregulation.

Solvation

The interaction of a solvent with a dissolved solute.

Solution

Solute + Solvent = ?

hydration shell

The water surrounds the solute, forming a "?" around the solute.

hydrogen bonds

Polar molecules readily dissolve in water because of the ? that form between the water molecules and the hydroxyl groups of the polar substance.

chemically interact

Nonpolar molecules will NOT readily dissolve in water because they cannot ? with water, a polar substance.

Osmosis

When water diffuses across a cell membrane, this process is called ?

selectively permeable membrane

Water diffuses across the ?, which does not allow certain solutes dissolved in the water to travel across.

lower water concentration, higher solute concentration

Water will move from the side of the membrane that has a higher water concentration and therefore lower solute concentration to the side of the membrane that has a ? and therefore ? until equilibrium is reached.

more concentrated solution

Water will move from a more dilute solution (high water concentration and low solute concentration) to a ? (low water concentration and high solute concentration) in an effort to reach equilibrium.

net (overall)

Once equilibrium is reached, there will be equal water and solute concentrations on both sides of the membrane, but there will be no ? movement of water in either direction.

aquaporins

Water can also move through channel proteins called ? in the cell membrane.

extracellular solution

The solution outside the cell is called the ?

intracellular solution

The solution inside the cell is called the ?

tonicity

The ability of an extracellular solution to make water move into or out of a cell by osmosis is known as its ?

osmolarity

A solution's tonicity is related to its ?, which is the total concentration of all solutes in the solution.

hypotonic

A solution with low osmolarity has fewer solute particles per liter of solution than another, and is called ?

hypertonic

A solution with high osmolarity has more solute particles per liter of solution than another, and is called ?

isotonic

Solutions with equal osmolarities are ?

hypotonic

If the extracellular fluid has lower osmolarity than the fluid inside the cell, it’s said to be ? to the cell, and the net flow of water will be into the cell.

hypertonic

If the extracellular fluid has a higher osmolarity than the cell’s cytoplasm, it’s said to be ? to the cell, and water will move out of the cell to the region of higher solute concentration.

isotonic solution

In an ? the extracellular fluid has the same osmolarity as the cell, and there will be no net movement of water into or out of the cell.

lysis

If too much water moves in, the animal cell could swell to the point of bursting the cell membrane. This is called ? and the cell is said to be lysed.

turgor pressure

Pressure of the cell membrane on the cell wall due to water coming into the cell is called ? and keeps plant stems from wilting. A plant cell in this state is considered turgid.

shriveled or crenated

When water moves out of the cell, the animal cell shrinks like a raisin in the sun, and the cell is said to be ?.

plasmolyzed

Water will move out of the plant cell, and the cell membrane will pull away significantly from the cell wall. In this situation, the cell is considered ?.

osmoregulation

Some organisms have adaptations to allow them to maintain the correct water and solute balance inside their cells. This is called ?

contractile vacuole

Paramecia solve the problem of excess water entering their cells by using an organelle called a ? that can pump water out of the cell in order to maintain homeostasis.

normal saline

Tissues or organs to be used in medical procedures must be bathed in a solution with the same osmolarity as the cytoplasm to prevent osmosis. Usually an isotonic sodium chloride solution is used, which is called ?

pressure

Water potential is a quantitative measurement of water’s tendency to move in response to forces such as solute concentration gradients and/or ?

decreases

As solute concentration increases, the water potential of a solution ?

increases

As the pressure of a solution increases, the water potential of that solution also ?

into

Water will move ? a cell placed in a hypotonic solution.

out of

Water will move ? a cell placed in a hypertonic solution.