Question

During the life cycle of red blood cells, which of the following statements is true?

1) The globin portion of hemoglobin is degraded to bilirubin by the liver.
2) RBCs are unable to synthesize proteins, grow, or undergo mitotic division.
3) RBCs have a life span of about 70-80 days.
4) The heme portion of hemoglobin is broken down to amino acids.
5) Old red blood cells are destroyed by macrophages in the kidneys.

Answer 1

During the life cycle of red blood cells, RBCs are unable to synthesize proteins, grow, or undergo mitotic division. The globin portion of hemoglobin is degraded into amino acids and the heme portion is broken down into bilirubin by the liver.

Step-by-step explanation:

Erythrocytes, or red blood cells (RBCs), are unable to synthesize proteins, grow, or undergo mitotic division. They have a life span of about 120 days, after which they are removed by macrophages in the bone marrow, liver, and spleen. The globin portion of hemoglobin is broken down into amino acids, which can be recycled for protein synthesis, while the heme portion is degraded into bilirubin by the liver. Therefore, statement 2 is true.