1. Biology Chapter 3 3B-2 Transportation Across the Membrane

2. Review Question  1. Explain the difference between simple diffusion and passive mediated transport  Simple diffusion- a substance crosses directly through the membrane from a higher concentration to a lower concentration  Passive mediated transport- requires a membrane transport protein for the substance through the membrane

3. Review Question  2. Explain the similarities and differences between passive mediated transport and active transport  Similarities: They both use carrier proteins  Differences: Passive also uses channel proteins and requires no cellular energy  Active transport requires cellular enegry and transports substances against the concentration gradient

4. Review Questions  3. List and Explain the difference between the two types of membrane transport proteins  Channel proteins form pores through the membrane-they do not bind to the substance being transported and do not change shape  Carrier Proteins- bind to the substance and change shape  Both are specific to the substance they allow to pass through the membrane

5. Review Questions  4. Describe the process of Endocytosis  A cell contracts the substance to be transported  The membrane folds around the substance  One it is surrounded- the membrane pinches off resulting in a membrane-bound vacuole

6. Things to know  Phagocytosis (93)  Active Transport (92)  Passive transport (91)  Pinocytosis (93)  Passive Mediated Transport (91-2)