22.  Osmosis is the diffusion of water across a membrane in response to the concentration of one or more of the ______. 

37. What is the main component of an animal cell membrane?  

44. THINK:  Matt is studying how the protein transferrin enters cells. He examines cells that have taken up transferrin, and finds clathrin-coated vesicles. What mechanism was used to take transferrin into the cell?  

28. A type of transport of a solute across a membrane, up its concentration gradient, using protein carriers driven by the expenditure of chemical energy (ATP) is known as  

24. Osmosis occurs as water can cross the lipid bilayer through specialized channels for water movement called ________________.  

38.  The splitting of water and the generation of oxygen occur where?  

27. Pyruvate oxidation in eukaryotic cells occurs in the ________.  

8. Schleiden and Schwann stated the “cell theory,” which in its modern form says: 

10. A calorie is the commonly used unit of chemical energy. It is also the unit of _________.

Write (fully) one of the two most important rules of retail.