Each hemoglobin molecule is made of four subunits, each containing a heme group that can bind one molecule of oxygen. Therefore, one molecule of hemoglobin can bind four molecules of oxygen. Oxyhemoglobin is hemoglobin bound by oxygen, and it gives oxygen-rich blood a red color.ach hemoglobin molecule is made of four subunits, each containing a heme group that can bind one molecule of oxygen. Therefore, one molecule of hemoglobin can bind four molecules of oxygen. Oxyhemoglobin is hemoglobin bound by oxygen, and it gives oxygen-rich blood a red color.
The First Reich was the Holy Roman Empire. There is little agreement as to when it was founded. Most German historians date the foundation from the coronation of Otto I in 962. That 'empire' had a continuous existence till 1806. The Second Reich was created by Bismarck in 1871 and lasted till 1918.
The term derives from the Germanic word meaning realm in general, but is typically used in German to designate a kingdom or an empire, especially the Roman Empire. The terms Kaisertum and Kaiserreich are used in German to more specifically define an empire led by an emperor. Reich is comparable in meaning and development (as well as descending from the same Proto-Indo-European root) to the English word realm (via French reaume kingdom from Latin regalis royal).