section_path: Distinguishing features/Mitochondria
section_name: Mitochondria
paragraph_text: Mitochondria
  
  Mitochondria are organelles in eukaryotic cells. The mitochondrion is commonly called "the powerhouse of the cell", for its function providing energy by oxidising sugars or fats to produce the energy-storing molecule ATP. Mitochondria have two surrounding membranes, each a phospholipid bilayer; the inner of which is folded into invaginations called cristae where aerobic respiration takes place.
  
  Mitochondria contain their own DNA, which has close structural similarities to bacterial DNA, from which it originated, and which encodes rRNA and tRNA genes that produce RNA which is closer in structure to bacterial RNA than to eukaryote RNA.
  
  Some eukaryotes, such as the metamonads Giardia and Trichomonas, and the amoebozoan Pelomyxa, appear to lack mitochondria, but all contain mitochondrion-derived organelles, like hydrogenosomes or mitosomes, having lost their mitochondria secondarily. Henneguya zschokkei lack of mitochondria and mitochondrial DNA. They obtain energy by enzymatic action in the cytoplasm.