COEnzyme Q-10 is an important antioxidant found in high concentration in human heart and liver, kidney, spleen and pancreas tissue. Co-Q10 is part of the cells electron transport system. Co-Q is a powerful antioxidant that can decrease the proliferation of free radicals and lighten the load on the immune system. Co-Q is not found just within the cells organelles, but also is naturally present in the cell membranes. Another function of Co-Q is to make sure the cells plasma membrane remain flexible. The fluidity of the membranes is crucial for proper physical performance because membrane fluidity affects membrane receptors, carriers and enzymes.