The three golden lions on a red background, symbolising England, occupy the first and fourth quarters. The Arms of Scotland, a red lion rearing on its hind legs inside a red border, are in the second quarter, and the Arms of Ireland's golden harp with silver strings on a blue background-are in the third quarter.
Once it is reduced to QH2, ubiquinone delivers its electrons to the next complex in the electron transport chain. Q receives the electrons derived from NADH from complex I and the electrons derived from FADH2 from complex II, including succinate dehydrogenase. This enzyme and FADH2 form a small complex that delivers electrons directly to the electron transport chain, bypassing the first complex.
The change in the form of the active nicotinamide group in NADH is indicated above. It accepts two electrons and a hydrogen in reaching the high energy state. The NAD + is used in redox reactions in the cell and acts as a reducing agent.