Final answer:
The combination of protoporphyrin and Fe²⁺ to form heme via ferrochelatase is known as Heme Synthesis, which is a crucial biological process for forming hemoglobin and cytochrome proteins.
Step-by-step explanation:
The process by which protoporphyrin and Fe²⁺ combine to form heme via the enzyme ferrochelatase is called Heme Synthesis. This is an important step in the biosynthesis of heme, which is an iron porphyrin structure synthesized in the reticuloendothelial cells of adults. Heme is essential for many biological functions, as it becomes part of hemoglobin when combined with globin and plays a critical role in oxygen transport in the blood. Additionally, heme is a prosthetic group in various heme-containing proteins, such as cytochromes, which are involved in electron transport and cell respiration.