Question

Percentage of haemoglobin in RBCs is
A) $10\%$
B) $20\%$
C) $34\%$
D) $48\%$

Answer 1

Haemoglobin is the pigment that gives a red colour to the blood. The red pigment consists of a protein component and an iron complex which is a porphyrin derivative. Haemoglobin is a quaternary structure that is made up of alpha and beta chains and they are linked covalently.

Step by step answer:
In mammals, the dry content of the protein is $96\%$ of the RBC dry weight and around $35\%$ of the total content including water.
-Haemoglobin can bind to the oxygen and can dissolve the oxygen in the blood. In mammals, the haemoglobin can bind up to four oxygen molecules. It can also transport other gases and some of the body's respiratory carbon dioxide as carbaminohemoglobin, in which carbon dioxide is bound to the haemoglobin protein rather than the oxygen. They also carry important regulatory molecules such as nitric oxide.
-Haemoglobin is even found outside red blood cells. The other cells which have haemoglobin are macrophages, lungs, alveolar cells, and even in some tissues, etc. When in tissues the haemoglobin has a non-oxygen-carrying function which acts as an antioxidant. When there is an excess of glucose in the blood the glucose attaches to haemoglobin in turn raising the haemoglobin.
Hence, the correct answer is $34\%$, which is option C.

Additional information:
When we are in higher altitudes like mountains our RBC count will increase because at higher altitudes the oxygen levels will decrease and it will remain like this for several days so to make it normal there are several medications like gentamicin and methyldopa which increases RBC count. Methyldopa is used to treat high blood pressure which will relax the blood vessels which allows the blood to flow properly and normally.

Note: If there is blood loss or damage to the bone marrow, they reduce total RBC count and they will lower the total haemoglobin content. Haemoglobin levels are also low in certain patients who have abnormal cells shaped like sickle cell anemia whose RBC is sickle-shaped. These types of abnormal cells are damaged or destroyed easily. To distinguish these cells haemoglobin electrophoresis is used.