The red , oxygen carrying pigment in the RBCs of vertebrates is haemoglobin. It consists of the protein globin ( polypeptide ) united with the pigment hem ( Heme ). It develops in the cell of the bone marrow. Haemoglobin, often referred to as the body’s oxygen conductor, plays a central role in transporting oxygen from the lungs to every cell in the body. The standard abbreviation for haemoglobin is “Hb”.
Structure Of Haemoglobin
The structure of haemoglobin is composed of four subunits, each containing a heme group.
- Primary structure
The primary structure of haemoglobin refers to the linear sequence of amino acids that make up each subunit. It is a globular protein consisting of four polypeptide chains: two alpha (α) chains and two beta (β) chains in adults. The primary structure is encoded by the genes in our DNA.
- Secondary structure
The secondary structure involves the folding of the polypeptide chains into specific shapes. In it, the secondary structure includes alpha-helices and beta-sheets. These structures contribute to the overall three-dimensional shape of the protein.
- Tertiary Structure
The tertiary structure is the three-dimensional arrangement of the entire polypeptide chain. Haemoglobin’s tertiary structure results from interactions between amino acid side chains, including hydrogen bonds, disulfide bonds, and hydrophobic interactions. This level of structure is critical for it’s function.
- Quaternary Structure
It’s quaternary structure is the result of the interaction between its four subunits. The two alpha chains and two beta chains come together to form a functional haemoglobin molecule. The quaternary structure is essential for the cooperative binding of oxygen – as one oxygen molecule binds to one subunit, it facilitates the binding of subsequent oxygen molecules.
- Heme Groups
Each subunit of haemoglobin contains a heme group, which is a complex structure containing iron at its center. The iron atom is where oxygen binds. It can bind up to four oxygen molecules, one for each heme group.
- Oxygen Binding and Release
It undergoes a conformational change upon binding with oxygen. This change enhances the affinity of the remaining subunits for oxygen, allowing it to bind oxygen cooperatively. In tissues where oxygen is needed, this process is reversed, and it releases oxygen to the cells.
- At birth – 23g/dl because RBC count is more.
- At the end of 3 months – 10.5g/dl, as an infant is totally milk feed which is devoid of iron.
- After 3 months, it increases gradually and at the end of 1 year it becomes 12.5g/dl.
- Adults –Males : 14 – 18 g/dl (Average : 15.5 g/dl), Females : 12 – 15.5 g/dl (Average : 14 g/dl)
- Clinically 14 – 18 g/dl haemoglobin irrespective of sex regarded as 100% haemoglobin.
Synthesis of Haemoglobin
Synthesis of it requires the provision of nutrients, e.g proteins, vitamins, minerals (specially iron). It only takes place in the developing RBCs.
Factors controlling haemoglobin formation
- Role of proteins : A low protein intake decreases haemoglobin regeneration even in the presence of excess iron. The limiting factor here is lack of globin formation.
- Role of minerals
- Iron – It is useful in the formation of haem.
- Copper : It is useful in the promotion of absorption, metabolism and utilisation of iron.
- Cobalt is necessary for the manufacture of vitamin B12 by bacterial action in the lumen of GIT.
- Calcium increases iron absorption from GIT.
- Role of vitamins : Vitamin C, Vitamin B12 and folic acid is useful in synthesis of nucleic acid which in turn is required for development of RBCs.
Functions Of Haemoglobin
- Facilitate transport of oxygen from lungs to the tissues.
- Facilitate transport of CO2 from the tissues to the lungs.
- Being a protein, it acts as an excellent acid-base buffer. It is responsible for 70% buffering power of the whole blood.
Low Haemoglobin : Causes and solutions
Low haemoglobin, a condition known as anemia, can have various causes and may require different treatments depending on the underlying reason. It is a protein in red blood cells that carries oxygen from the lungs to the rest of the body. Common causes of low haemoglobin include nutritional deficiencies ( iron deficiency, vitamin B12 deficiency ), Chronic diseases ( inflammatory disorders, chronic kidney disease ), genetic conditions and bone marrow disorders. Iron supplementation, dietary changes, and treating underlying conditions are key strategies to restore optimal levels.
High Haemoglobin : Unveiling the triggers
High haemoglobin levels, known as polycythemia or erythrocytosis, can have various causes. It is a protein in red blood cells that carries oxygen from the lungs to the rest of the body. Common causes are dehydration, chronic lung diseases, heart or lung disorders, bone marrow disorders, living at high altitudes, kidney disorders and genetic factors.
Lifestyle Practices for Haemoglobin Harmony
Beyond nutrition, lifestyle choices play a pivotal role in haemoglobin regulation. Adequate exercise, managing stress, and avoiding excessive alcohol intake contribute to overall health and help maintain its balance. Here are some lifestyle practices :
- Nutrient rich diet – Consume a balanced diet rich in iron, vitamin B12, folic acid, and vitamin C. Include foods such as lean meats, fish, poultry, beans, lentils, dark green leafy vegetables, nuts, seeds, and fortified cereals.
- Iron absorption boosters – Pair iron-rich foods with vitamin C sources (citrus fruits, strawberries, bell peppers) to enhance iron absorption. Conversely, avoid consuming calcium-rich foods or supplements with iron-rich meals, as calcium can inhibit iron absorption.
- Regular Exercise – Engage in regular physical activity to promote overall cardiovascular health and stimulate the production of red blood cells.
- Avoid smoking and alcohol consumption – Quitting smoking contributes to better oxygen transport and overall cardiovascular health. Excessive alcohol intake can interfere with the absorption of essential nutrients, including iron. Limit alcohol consumption to moderate levels or avoid it altogether to promote optimal nutrient absorption.
- Limit caffeine intake – While moderate caffeine intake is generally safe, excessive consumption may interfere with iron absorption. Be mindful of your caffeine intake, especially during meals.
In the intricate dance of health, haemoglobin harmony is a crucial partner. By understanding the causes of imbalances and adopting a holistic approach encompassing nutrition, lifestyle, and medical interventions, individuals can pave the way for optimal haemoglobin levels and, consequently, enhanced overall well-being. This blog aims to empower readers with knowledge and actionable steps to embark on a journey towards haemoglobin harmony and optimal health.