The number of subunits present in haemoglobin are:
Subunits present in haemoglobin are
[AIIMS 2003]
Haemoglobin contains 0.334% of iron by weight . The molecular weight of haemoglobin is approximately 67200. The number of iron atoms present in one molecule of haemoglobin is
(a) 4 (b) 6
(c) 3 (d) 2