FIG. 7.

Circadian coupling of mitochondria and ROS homeostasis. Daily feeding/fasting cycle dictates nutrient flux to mitochondria, where the nutrient oxidation is coupled with production of energy-rich ATP molecules in the process of oxidative phosphorylation. Due to electron leakage, mitochondrial energy production is associated with ROS generation. Excessive ROS lead to oxidative damage and contribute to diseases, and impact longevity. Almost every stage of the nutrient oxidation/energy production chain and mitochondrial antioxidant defense is under circadian control. The circadian clock is intertwined with daily rhythms, including the feeding cycle. Due to that, the circadian clock is capable of coordinating ROS homeostasis with organism daily activity and optimizes metabolism to reduce the risk of disease and delay aging.