By now we have a pretty good foundation for learning more about cells. We just explored the the cell theory in some detail. Let's focus on one of the components of the cell theory: Cells are the basic units of life.

We can think of cells as biological factories, each with the equipment, assembly lines, and transportation systems to make whatever it needs for energy or to repair its structures. Many of the functions of a cell are carried out by organelles – distinct structures or compartments within a eukaryotic cell that perform specific tasks. We learned a bit about organelles earlier in this chapter, and now we'll have a chance to explore them in much more depth.

This activity is a virtual tour of a cell. We'll build a human liver cell from scratch, starting with the cytosol and adding all the organelles and support structures. As we add each component, we'll explore its structure and function in detail. We'll also consider the important interrelationships of several organelles. Once we've built a cell and understand the function of all its components, we'll surround it with a variety of extracellular structures so we can begin to see how cells communicate with one another and come together to form tissues and organs.

Objectives