A researcher is attempting to isolate rough ER microsomes using ultracentrifugation (Note: microsomes are fragments of the ER wh
ich result from the cell homogenization and centrifugation techniques). Which of the following would indicate contamination of the rough ER with another organelle?
Catalase is an enzyme that is found in practically all living beings for their important function of catalyzing the reaction of decomposition of hydrogen peroxide to water and oxygen. Catalase is primarily found in organelles involved in respiration and photorespiration, such as mitochondrias and peroxisomes. If catalases are found in rough ER microsomes it would indicate that rough ER has been contaminated with another organelle, such as mitochondrias and peroxisomes.
