Exam 2
Although I try to cover all materials thoroughly in these questions, anything covered in lecture may appear on the exam. Membrane Transport 1. Describe the cell permeability and membrane transport. What can enter/exit the cell on its own? What requires assistance? Why? 2. Describe membrane potential. What is it? How is it established? How does it influence the transport of charged molecules? What are the components of the electrochemical gradient? 3. What are the different types of membrane transport? Describe each in detail. Which move solutes with their electrochemical gradient? Against? Which require energy input? Which show saturation kinetics? Competitive inhibition? 4. What can cross the cell membrane by simple diffusion? What cannot? Describe and define diffusion, osmosis, tonicity (hypertonic, hypotonic, isotonic—in animals and in plants). What does it cost animal cells not to have a cell wall or water vacuole? Does this demonstrate saturation kinetics? Why or why not? 5. Describe and understand facilitated diffusion in detail. What type of proteins are involved? How do they work? Which are faster? What types of carrier proteins and channel proteins are there? Know and understand the examples described in lecture. Do these show saturation kinetics and what does that mean? 6. Describe active transport in detail. What energy sources can be used to move molecules against their concentration gradients? Do these show saturation kinetics and what does that mean? Understand the Na/K pump, its role in the cell, coupling the Na gradient with the flow of organic molecules, and the membrane potential. 7. Describe a nerve and how a signal is sent down its axon. Describe the action potential. What is depolarization and how does it occur? Describe the voltage-gated Na+ channels and their role in the action potential. What is the role of voltage-gated K+ channels and what is