Central Idea
- A groundbreaking study published in Nature has unveiled an unexpected revelation: haemoglobin is not exclusive to RBCs.
- Scientists from China have discovered that chondrocytes, the cells responsible for cartilage production, also produce haemoglobin, which appears vital for their survival.
- For decades, textbooks have taught that haemoglobin resides solely in red blood cells (RBCs), responsible for making blood red and transporting oxygen.
| Cartilage: A tough, flexible connective tissue found throughout the human body, providing structural support and reducing friction between bones. |
About Haemoglobin
| Fact |
Description |
| Definition |
A protein found in red blood cells that transports oxygen from the lungs to tissues and organs. |
| Molecular Structure |
Composed of four subunits: two alpha-globin chains and two beta-globin chains. |
| Iron-Binding |
Each subunit contains an iron atom that binds to oxygen, forming oxy-hemoglobin. |
| Oxygen Transport |
Carries oxygen from the lungs to tissues and releases oxygen for cellular respiration. |
| Color |
Gives red blood cells their red color when oxygenated and appears bluish when deoxygenated. |
| Carbon Dioxide Transport |
Aids in transporting carbon dioxide and hydrogen ions from tissues back to the lungs for exhalation. |
| Hemoglobin Variants |
Different types of hemoglobin, with HbA being the most common. Variants can result from genetic mutations. |
| Hemoglobin Levels |
Vary by individual and are measured in grams per deciliter (g/dL). Normal levels range from 12 to 18 g/dL. |
| Hemoglobin Disorders |
Genetic disorders like sickle cell disease and thalassemia are characterized by abnormal hemoglobin production. |
| Iron Metabolism |
Adequate iron levels are essential for hemoglobin synthesis. Iron is a key component of heme in hemoglobin. |
| Fetal Hemoglobin |
Fetal hemoglobin (HbF) has a higher oxygen affinity and aids in oxygen transfer from mother to fetus. |
| Hemoglobin Tests |
Used for diagnosing anemia, assessing health, and monitoring medical conditions. |
| Oxygen Saturation |
Measured as the percentage of hemoglobin molecules bound to oxygen, often using a pulse oximeter. |
New Breakthrough: Haemoglobin Bodies (Hedy)
- Pathologists in China researching bone development, stumbled upon spherical structures resembling RBCs within chondrocytes.
- These structures, termed “haemoglobin bodies” or Hedy, contained haemoglobin and formed large, membraneless blobs, akin to phase separation in oil and water.
Functionality of Hedy
- Essential for Survival: Experiments on genetically modified mice revealed that chondrocytes without haemoglobin experienced cell death, emphasizing Hedy’s vital role.
- Oxygen Transport: Similar to RBCs, haemoglobin in chondrocytes likely serves as an oxygen store and supplier, preventing hypoxic stress (low-oxygen conditions) in cartilage cells.
Haemoglobin’s Broader Implications
- New Research Avenues: The discovery bridges gaps between haematology and skeletal biology, paving the way for further exploration into the relationship between haemoglobin and stem cell fate in growth plates.
- Potential for Joint Disease Insights: Functional haemoglobin in cartilage raises possibilities of its involvement in joint diseases and bone deformities, offering fresh insights into disease mechanisms.
Try this PYQ:
Excessive release of the pollutant carbon monoxide (CO) into the air may produce a condition in which oxygen supply in the human body decrease. What causes this condition?
(a) When inhaled into the human body, CO is converted into CO2
(b) The inhaled CO has much higher affinity for haemoglobin as compared to oxygen
(c) The inhaled CO destroys the chemical structure of hemoglobin
(d) The inhaled CO adversely affects the respiratory center in the brain
Post your answers here.
