The 2009 Molecular and Cellular Bioenergetics Gordon Research Conference will be held at Proctor Academy, Andover, New Hampshire from June 7-12, 2009. The opening Session 1 has the title ‘Mitochondria, Oxidative Stress and Aging’ and will discuss the status of the mitochondrial theory of aging and the roles of mitochondrial mutations. A traditional strength of the Conference lies in the structure-function and assembly of energy transduction components, and this will be continued, with Session 2 which will cover Respiratory Chain Complex I Structure and Function, where the as yet unrealized goal is to obtain a structure of the complete complex and to gain insight into the presently obscure mechanism of proton pumping. Session 3 will cover the V- and P-ATPases that act to pump protons, sodium, calcium and other ions at non-mitochondrial membranes. These pumps differ from the F-ATP synthase in the mitochondrion, and this comparative analysis gives insight into the evolution of each class of pump. Session 4 is an innovation that encapsulates the central theme of the Conference – namely to bring together biophysicists with their knowledge of structure and mechanism and ‘mitochondrial physiologists’ trying to understand how Mitochondrial Dysfunction impacts on the major neurodegenerative diseases, including Parkinson’s, Alzheimer’s and Huntington’s diseases. This concept in continued in Session 5 – new aspects of mitochondrial metabolism, where we shall be covering mitochondrial energetics in both type 1 (insulin secretion) and Type 2 (insulin resistance) diabetes, hearing recent advances on the Warburg effect in cancer and understanding the role of novel transporters in mitochondrial metabolism. Session 6 will be organized as a series of round-table discussions focusing on the most controversial aspects of the current field. Session 7 will focus on the unanswered questions on the mechanisms of proton pumping by Complexes III and IV, while Session 8 deals with the structure and mechanism of the F1-ATP synthase, including the nature of the Fo proton ‘turbine’. The final Session 9 bridges bioenergetics and cell biology by focusing on the roles of mitochondrial fission, fusion and function.