Hemoglobin

**Semantic type:** Amino Acid, Peptide, or Protein

**Definition:** The red respiratory protein of erythrocytes, consisting of approximately 3.8% heme and 96.2% globin (64.5 KD), which as oxyhemoglobin (HbO2) transports oxygen from the lungs to the tissues where the oxygen is readily released and HbO2 becomes Hb.

**Synonyms:** - Hb - Hgb - hemoglobin