Campbell's Biology, 9e (Reece et al.) Chapter 7 Membrane Structure and Function Membranes and membrane transport are fundamental to cellular life. The concepts in this chapter require integration of concepts from previous chapters: the nature of water and hydrophobic versus hydrophilic molecules, the properties of lipid molecules and their role in regulating membrane fluidity, and the roles of proteins and carbohydrates in membrane function. The concepts of ion transport and electrochemical gradients across membranes are important foundations for the following chapters on energy metabolism. Finally, the bulk transport phenomena have important clinical significance in the immune system, during invasion by pathogens, and in cell signaling. Multiple-Choice Questions