haemoglobin is a chromoprotein having 4 atoms of Fe in each molecule. analysis showed 0.35% Fe. what is the molecular weight of haemoglobin?

To determine the molecular weight of hemoglobin based on the given information, we can use the percentage of iron (Fe) in the molecule along with the known atomic weights of the elements involved. Hemoglobin is a complex protein that contains iron, which is crucial for its function in oxygen transport.

Understanding the Composition of Hemoglobin

Hemoglobin is composed of four heme groups, each containing one iron atom. Therefore, in one molecule of hemoglobin, there are four iron atoms. The molecular weight of hemoglobin can be calculated if we know the total weight of iron in the molecule and its percentage composition.

Step-by-Step Calculation

• Identify the percentage of iron: The analysis shows that hemoglobin contains 0.35% iron.
• Determine the weight of iron in one molecule: Since there are four iron atoms in hemoglobin, we can express the total weight of iron in terms of the molecular weight of hemoglobin (M). The weight of iron in hemoglobin can be represented as 0.0035M (because 0.35% is the same as 0.0035 in decimal form).
• Calculate the weight of iron: The atomic weight of iron (Fe) is approximately 55.85 g/mol. Since there are four iron atoms, the total weight of iron in hemoglobin is 4 × 55.85 g/mol = 223.4 g/mol.
• Set up the equation: We can now set up the equation based on the weight of iron: 0.0035M = 223.4 g/mol.
• Solve for M: Rearranging the equation gives us M = 223.4 g/mol / 0.0035. Performing this calculation yields:

M = 63,714.29 g/mol.

Final Result

Thus, the molecular weight of hemoglobin is approximately 63,714 g/mol. This value reflects the complex structure of hemoglobin, which is essential for its role in transporting oxygen in the blood.

Additional Insights

It's interesting to note that the molecular weight of hemoglobin can vary slightly depending on its specific type (for example, adult hemoglobin vs. fetal hemoglobin) and its state (oxygenated vs. deoxygenated). However, the calculation above provides a good estimate based on the given iron content.