Diffusion/Osmosis, Diffusion and Osmosis

Diffusion

What is the movement of molecules from an area high concentration to an area of low concentration?

Concentration gradient and temperature

What are two factors that influence the rate of diffusion?

Faster

A steeper concentration gradient causes diffusion to move faster or slower?

Slow down

What will happen to the rate of diffusion if the temperature is decreased?

Speed up

What will happen to the rate of diffusion if the temperature is increased?

Osmosis

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

Isotonic

The cell in the picture is sitting in what type of tonic solution?

Remain the same. This is the ideal environment.

What will happen to a red blood cell placed in an isotonic solution?

hypotonic

The cell in the picture is sitting in what type of tonic solution?

swell and possibly lyse (pop)

What will happen to a red blood cell placed in a hypotonic solution?

Hypertonic

The cell in the picture is sitting in what type of tonic solution?

No, it continues to go back and forth at equal rates.

Once equilibrium is reached in diffusion and osmosis does movement stop?

Back and forth in equal amounts

Which way will the water move?

Isotonic solution

The cell is sitting in an ________________ solution.

Selective Permeability

Plasma membrane allows certain molecules cross it depending on size and polarity; small nonpolar molecules pass through easily

Passive Transport (Diffusion)

Requires no energy to move molecules down their concentration gradient(from high to low concentration)

Active Transport

Requires energy and carrier proteins to move molecules down or against their concentration gradient

Solvent

Dissolving agent

Solute

Substance dissolved in solvent

Osmosis

Diffusion of water

Hypotonic Solution

Low solute concentration; cells burst.

Hypertonic Solution

High solute concentration, cells shrivel up (hyper- think high energy)

Isotonic Solution

Concentration of the solutes on both sides of the membrane are equal; at osmotic equillibrium

Temperature and Diffusion

The higher the temperature, the faster the rate of diffusion

Osmotic equilibrium

Osmotic equilibrium is the term used to indicate that the concentration of a solute in water is the same on both sides of a semi-permeable membrane.