2.1. Cell physiology[[Student version, December 8, 2002]] 37
Figure 2.7: (Schematic; scanning electron micrograph.) (a)Locations of various internal structures in the mito-
chondrion. The ATP synthase particles are molecular machines where ATP production takes place (see Chapter 11).
They are studded into the mitochondrion’s inner membrane, a partition between an interior compartment (the ma-
trix) and an intermembrane space. (b)Interior of a mitochondrion. The sample has been flash-frozen, fractured,
and etched to show the internal matrix enclosed by the folds of the inner membrane. [From K. Tanaka, Int. Rev.
Cytol. 68(1980)111.] [Copyrighted figure; permission pending.]
Figure 2.8: (Sketch; electron micrograph.) Gross anatomy of a white blood cell. A single plasma membrane
surrounds the cell. Other organelles are visible, most of them small compartments defined by membranes. Other
examples of secretory vesicles include the synaptic vesicles in neurons, shown in Figure 2.9 and discussed in Chap-
ter 12. Chapters 10 and 11 will discuss the osmotic regulation mechanism that keeps the cell’s interior full of fluid.
[Copyrighted figure; permission pending.]
internal energy-carrying molecule ATP. Instead of metabolizing food, however, they