Diagram of mitochondria

Biological energy conversion in mitochondria is carried out by the membrane protein complexes of the respiratory chain and the mitochondrial ATP synthase in the inner membrane cristae. Recent advances in electron cryomicroscopy have made possible new insights into the structural and functional arrangement of these complexes in the membrane, and how they change with age. This review places these advances in the context of what is already known, and discusses the fundamental questions that remain open but can now be approached. Mitochondria are the powerhouses of the cell. In all eukaryotes that do not depend on photosynthesis, the mitochondria are the main source of adenosine triphosphate (ATP), the energy-rich compound that drives fundamental cell functions. These functions include force generation (for example, in muscle contraction and cell division), the biosynthesis, folding and degradation of proteins, and the generation and maintenance of membrane potentials. ATP is produced on a massive scale in the human body, amounting to 50Â kg per day in a healthy adult, but considerably more in a long-distance runner. ATP is generated by the mitochondrial ATP synthase from ADP and phosphate ions. These are the products of ATP hydrolysis at the sites where energy is needed in the cell. Apart from cellular respiration and ATP synthesis, mitochondria have numerous other essential functions, including the production of NADH and GTP in the citric acid cycle, the biosynthesis of amin...

Dominic Corsini Dominic Corsini has an extensive educational background with a B.S. in Secondary Biology and General Science with a Minor in Environmental Education, an M.Ed. in Educational Leadership, an M.S. in Biology, and a K-12 Principal Certification Program. Corsini has experience as a high school Life, Earth, Biology, Ecology, and Physical Science teacher. What Is Cellular Respiration? All living things need energy to survive. Without energy, our cells cannot function and our bodies shut down. Life cannot exist without this constant supply of energy. But, where does it come from? The energy your body uses to pump blood through your veins, inhale air into your lungs, and move your eyes across this page is derived from cellular respiration. Cellular respiration is a multi-step process that converts the chemical energy in food into usable cellular energy in the form of adenosine triphosphate, or ATP. ATP is like the energy currency of cells. It is necessary for cellular function and sustaining your life. This ATP is produced primarily by an organelle called the mitochondria. Mitochondria are cellular organelles that synthesize ATP for our cells. Let's take a look at how cellular respiration works inside the mitochondria. Remember that cellular respiration is aimed at creating ATP. Typically this process is broken into three phases, or steps. Those phases are glycolysis, the Krebs cycle, and the electron transport chain (or ETC for short). We'll only focus on these lat...