Tell me some facts about hemoglobin with the given text as a reference
Hemoglobin��(haemoglobin��in��British English), abbreviated��Hb��or��Hgb, is the��iron-containing��oxygen-transport��metalloprotein��present in��red blood cells��(erythrocytes) of almost all��vertebrates (the exception being the fish family�� Channichthyidae )��as well as the tissues of some��invertebrates.Hemoglobin in��blood��carries oxygen from the respiratory organs (e.g.��lungs��or��gills) to the rest of the body (i.e.��tissues). There it releases the oxygen to permit��aerobic respiration��to provide energy to power functions of an organism in the process called��metabolism. A healthy individual human has 12��to 20��grams of hemoglobin in every 100��mL of blood.
1. Hemoglobin/Hb/Hgb is the��iron-containing��oxygen-transport��metalloprotein which is��present
 in��red blood cells��(erythrocytes) of almost all��vertebrates (the exception being the fish
 family�� Channichthyidae )��as well as the tissues of some��invertebrates
 2. Hemoglobin carries oxygen in blood from respiratory organs (e.g.��lungs��or��gills) to rest of the
 body(i.e. tissue).
 3. Metablolism is the energy to power functions of an organism. Hemoglobin releases the oxygen
 to permit��aerobic respiration .
 4. Healthy human have 12 to 25 grams of hemoglobin in every 100��mL of blood.