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 nitrogen center of pyridine features a basic lone pair of electrons. Because this lone pair is not part of the aromatic ring, pyridine is a base, having chemical properties similar to those of tertiary amines. The pKa of the conjugate acid is 5.25.ll the ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen atom donates its three hybridized electrons to the ring system, and its extra electron pair lies in the molecule plane, projecting outward, in the plane of the ring.