Question

question 38
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in the tissues, the oxyhemoglobin gives up oxygen molecules from which part of hemoglobin?
iron in heme groups.
carbon rings in heme groups.
beta chains in hemoglobin.
alpha chains in hemoglobin.

Explanation:

Hemoglobin consists of heme groups. Each heme group contains an iron atom. Oxygen binds to the iron in the heme groups of hemoglobin. When oxyhemoglobin reaches the tissues, it is the iron in the heme groups that releases the oxygen molecules. Carbon rings in heme groups are part of the heme structure but do not directly bind or release oxygen. Alpha and beta chains are polypeptide chains of the globin part of hemoglobin and are not the site from which oxygen is released (the globin part affects the conformation and oxygen - binding properties but the direct oxygen - binding and releasing site is the iron in heme).

Answer:

Iron in heme groups.