Question

One haemoglobin carries how many molecules of $O_2$?

• A. $4$
• B. $2$
• C. $6$
• D. $8$

Answer 1

Answer: (A)

$4$

Answer 2

$Hb$ contains a protein portion called globin and a pigment portion called haem. The haem portion consists of four atoms of iron, each capable of combining with a molecule of $O_2$. Thus, one $Hb$ carries $4$ molecules of $O_2$.