Question

Which of the following statements about hemoglobin and myoglobin structure are true? Select the five true statements. a) Each hemoglobin or myoglobin molecule can bind four oxygen molecules. b) Hemoglobin is a heterotetramer, whereas myoblobin is a monomer. c) Molecular oxygen binds irreversibly to Fe2+ in heme. d) Both hemoglobin and myoglobin contain a prosthetic group called heme, which contains a central iron atom. e) Heme is composed of an organic protoporphyron compenent and a metal atom. f) By itself, heme is not a good oxygen carrier. It must be part of a larger protein to prevent oxidation of the iron atom. g) Each iron atom can form six coordination bonds: one of these bonds is formed between iron and oxygen.

Answer 1

a) False

Because each hemoglobin can bind four oxygen molecules, Each myoglobin bind only single oxygen molecule

b) True

Hemoglobin is a heterotetramer, whereas myoblobin is a monomer.

c) False

Molecular oxygen binds irreversibly to Fe²⁺ in heme.

d) True

Both hemoglobin and myoglobin contain a prosthetic group called heme, which contains a central iron atom.

e) True

Heme is composed of an organic protoporphyron compenent and a metal atom.

f) True

By itself, heme is not a good oxygen carrier. It must be part of a larger protein to prevent oxidation of the iron atom.

g) True

Each iron atom can form six coordination bonds: one of these bonds is formed between iron and oxygen.