Question

question
which of the following is true of hemoglobin?
answer
hemoglobin molecules account for about 10% of an
erythrocytes proteins.
oxygen binds to the heme portion of hemoglobin, while
carbon dioxide binds to the globin portion.
hemoglobin consists of a single globular protein.
hemoglobin carries almost 100% of the carbon dioxide
transported in the blood.
i dont know yet

Explanation:

• Hemoglobin molecules account for about 95% of an erythrocyte's proteins, not 10%, so the first option is wrong.
• Hemoglobin consists of four globular proteins (two alpha and two beta chains), not a single one, so the third option is wrong.
• Hemoglobin carries about 20 - 25% of the carbon dioxide transported in the blood, not almost 100%, so the fourth option is wrong.
• Oxygen binds to the heme portion (which contains iron) of hemoglobin, and carbon dioxide can bind to the globin portion (amino - acid chains) of hemoglobin.

Answer:

Oxygen binds to the heme portion of hemoglobin, while carbon dioxide binds to the globin portion.