2401- Biochemistry I

Question 1

Give the characteristics of myoglobin.

Answer 1

1 subgroup and 1 heme group
Molecular weight - 16,700 and 153 aa
His F8 or His93 is the residue attached to myoglobin
8 helices A-Hj

Question 2

What is the state of iron in deoxymyoglobin?

Answer 2

Ferrous (Fe2+)

Question 3

At which site does bind to in the hemoglobin structure, “The Globin Fold”?

Answer 3

Distal histidine, E7

Note: it establishes a hydrogen bond with O2 and plays an important physiological role in discriminating between ligands.

Question 4

As it relates to the binding curves of myoglobin and hemoglobin, what is the significance of both curves?

Answer 4

Myoglobin has a high affinity for O2, therefore, at low PO2, its affinity would be greater to hemoglobin

Hemoglobin has a lower affinity to O2, thus as low levels the affinity would be less than to myoglobin.

At high PO2, both hemoglobin and my goblin would have similar affinities.