Passive Transport Review

What is diffusion?

• when molecules move from a low concentration to a high concentration 
• when molecules move from a high concentration to a low concentration.
• no movement 
• molecules move everywhere

What is the definition of  Selective Permeability?

• The movement of materials across the cell membrane that requires NO ENERGY from the cell.
  
• The movement of materials through (or across) the cell membrane
  
• The ability of the cell membrane to allow some things to pass through while preventing other things from passing through.
• The movement of molecules from an area of high concentration (where the molecules are more crowded together) to a area of low concentration (where molecules are more spread apart)
  

Osmosis

• diffusion of water molecules through a semi-permeable mebrane from an area of low concentration to an area of high concentration
• the diffusion of particles from an area of high concentration to an area of low concentration
• diffusion of water molecules through a semi-permeable membrane from an area of high concentration to an area of low concentration
• the diffusion of particles from an area of low concentration to an area of high concentration

Osmosis is the movement of _____ across a membrane.

• food
• energy
• oxygen
• water

_______ regulates what enters and leaves a cell.  

• Cell Membrane
• Nucleus
• Mitochondria
• Cytoplasm

Equilibrium?

• a large  amount of substance on  side of the cell and a small amount on the other side
• a small  amount of substance on  side of the cell and a large amount on the otherside
• equal amount of substance on either side of the membrane  
• no particles on either side of the a cell membrane

Which way will the water molecules move during osmosis?

• Out of the cell, so the cell shrinks.
• Out of the cell, so the cell swells.
• Into the cell, so the cell shrinks.
• Into the cell, so the cell swells.

If there is 5 percent water inside a cell and 5 percent water outside a cell

• more water will move inside the cell
• more water will move outside the cell
• There will be no movement of water cells

When both inside and outside of a cell have the same amount of water it is said that the cell has reached a state of

• Osmosis
• Diffusion
• Equilibrium

What does “high concentration area” mean?

• Spread out
• Tightly packed together
• Uncrowded
• Spacious