Diplomonads have modified mitochondria called mitosomes. These organelles lack functional electron transport chains and hence cannot use oxygen to help extract energy from carbohydrates and other organic molecules. Instead, diplomonads get the energy they need from anaerobic biochemical pathways, such as glycolysis. Structurally, diplomonads have two equal-sized nuclei and multiple flagella. Recall that eukaryotic flagella are extensions of the cytoplasm, consisting of bundles of microtubles covered by the cell's plasma membrane. They are quite different from prokarytic flagella, which are filaments composed of the globular protein flagellin attached to the cell surface.