Oxygen production of the water molecule) is released into the atmosphere. Oxygen is used in mitochondria to generate ATP during oxidative phosphorylation. The reaction for aerobic respiration is essentially the reverse of photosynthesis and is simplified as: In vertebrates, diffuses through membranes in the lungs and into red blood cells. Hemoglobin binds , changing color from bluish red to bright red ( is released from another part of hemoglobin through the Bohr effect). Other animals use hemocyanin (molluscs and some arthropods) or hemerythrin (spiders and lobsters). A liter of blood can dissolve 200 cm of . Until the discovery of anaerobic
Effect of spaceflight on the human body enough oxygen to the brain without the astronaut's fainting or becoming dizzy. "Under the effects of the earth's gravity, blood and other body fluids are pulled towards the lower body. When gravity is taken away or reduced during space exploration, the blood tends to collect in the upper body instead, resulting in facial edema and other unwelcome side effects. Upon return to earth, the blood begins to pool in the lower extremities again, resulting in orthostatic hypotension." In 2013 NASA published a study that found changes to the eyes and eyesight of monkeys with spaceflights longer than 6 months. Noted