As you've worked through this tutorial, you may have wondered how a process as complex as chemiosmosis evolved. As you'll see, basic components of chemiosmosis are believed to have been essential to the survival of early cells. These were conserved and modified through time while new ones were added. Interactions between cells created further opportunities for diversification and were another important factor driving the evolution of chemiosmosis.

What you'll learn in this topic

• several important innovations in chemiosmosis that allowed cells to adapt to changing conditions on earth.
• how the byproducts of chemiosmosis in some cells affected the evolution of others
• the role endosymbiosis played in the origin of mitochondria and chloroplasts

Your task is to follow the evolution of chemiosmosis during 4 critical eras in the earth's history. At each era, you'll determine how chemiosmosis allowed cells to capture and store energy efficiently.