Transport Across Membranes

The diffusion of water through a selectively permeable membrane. 

• active transport
• osmosis
• endocytosis 
• aquaporins 

The cell membrane is selectively permeable, which means...

• All materials can enter and leave the cell
• Certain things can enter while others cannot
• The cell manually sorts through all materials
• Only certain cells can interact with the cell.

How many layers is the lipid bilayer?

• 1
• 2
• 3
• 4

Two examples of passive transport are

• endocytosis and exocytosis
• diffusion and osmosis
• phagocytosis and pinocytosis
• None of the above

The movement of molecules against a concentration gradient

• simple diffusion
• facilitated diffusion
• active transport
• osmosis

The picture is an example of.....movement from low concentration to high concentration. 

• active tranport
• passive transport
• diffusion
• osmosis

What forms the channels and pumps in the phospholipid bilayer?

• carbohydrates
• proteins
• hydrophilic heads 
• lipids

A cell will _____________________ in a hypertonic solution.

• swell
• shrink
• will not change
• will explode

A cell will __________________ in a hypotonic solution.

• swell and perhaps burst (lyse)
• shrink
• the size of the cell will not change
• the size of the cell will change from large to small and from small to large

When the concentration of two solutions are the same. 

• hypertonic
• hypotonic 
• isotonic
• solute