9. What is the molecular
composition of hemoglobin?
Does the functionality of
hemoglobin as a protein
depend upon its tertiary or
upon its quaternary structure?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
Hemoglobin is a made of four
chains, each bound a
iron-containing molecular called a
heme . So the molecule
four polypeptide chains four heme
groups.

a protein composed association of
polypeptide , the functionality of
depends upon the
of its quaternary .