Q 1 Liposomes and black membranes are two major tools to the study the basic properties of biological membranes (Figs. 10-9, 10-10). Please list several potential usages for each of these two model systems. Explain your answers.

Q 2 Phospholipids and glycolipids are distributed asymmetrically in the plasma membrane bilayer. How can the lipid asymmetry in plasma membrane be detected? (How a cell generates this type of lipid asymmetry will be introduced in Ch. 12)

Q 3 Mild nonionic detergents can be used for solubilizing, purifying and reconstituting functional membrane proteins How can you test if they are really functional? 3

Q 4 What do these events have anything to do with osmosis and ion channels?

Q 5 In the central nervous system, many synapses are “inhibitory.” Please describe the ionic basis explaining how a synapse generates an inhibitory signal.

Q 6 The neuromuscular junction (Fig. 11-36) is very efficient (it takes a very short time to pass the signal from the motor neuron to the muscle), very faithful (an action potential always generates a contraction), and it can fully control the innervated skeletal muscle (one skeletal muscle only follows the “order” from one motor neuron). Explain how these characteristics are achieved. 6