Final answer:
Hemoglobin is not a carrier molecule in the electron transport chain; it is instead involved in oxygen transport within red blood cells.
Step-by-step explanation:
The types of carrier molecules found in the electron transport chain (ETC) include cytochromes, flavoproteins, metal-containing proteins, and ubiquinones (CoQ). However, hemoglobin is not a carrier molecule in the ETC; it is a protein found in red blood cells that carries oxygen. Cytochromes, such as cytochrome c, contain heme groups and transport electrons between complexes in the ETC. Ubiquinones also play a critical role in the ETC by transferring electrons between complexes. In contrast, proteins like hemoglobin are involved in oxygen transport but not in the mitochondrial electron transport chain.