Question

what is meant by hemoglobin ?

Answer 1

Matured mammalian RBCs do not have potential cell organelles including nucleus, Golgi bodies, mitochondria, ribosomes, centrioles and endoplasmic reticulum. It increases the surface area of RBCs and enables these to contain haemoglobin. Thus almost entire cytoplasm is filled with haemoglobin.

In the absence of cell organelles, the consumption of oxygen is very low. Anaerobic respiration occurs in RBCs.

Haemoglobin is a conjugated protein which is made up of a protein called globin and a non protein group heme (=haeme), hence the name haemoglobin.

Heme is an iron (Fe++)- porphyrin molecule or porphyrin complex. A mammalian haemoglobin molecule is composed of a complex of 4 heme molecules joined with 4 globin molecules. A red blood corpuscle has some 280 million haemoglobin molecules. Haemoglobin is the oxygen carrying pigment in most vertebrates except some ice fishes (Antarctic ice fish, Chaenocephalus) and eel larvae. Haemoglobin also occurs in the blood of some annelids and molluscs but in these invertebrates it remains in the plasma.

Answer 2

Hemoglobin is red coloured substance present in blood which gives the blood it’s identical red colour and it help blood to absorb oxygen.