The Latin verb supponere, meaning substitute, has several legitimate heirs in English, including supposititious (which dates from the early 17th century) and supposition (a 15th century addition).
Cellular respiration takes place in the organelles called mitochondria. The mitochondria take in glucose, a type of sugar, and change it in the presence of oxygen into an energy-rich molecule called ATP, or adenosine triphosphate. For every molecule of glucose, 36 molecules of ATP are made.
Cellular respiration combines reactants and releases products including a molecule called ATP, the energy providing molecule. The process of cellular respiration occurs inside cells inside the organelles called mitochondria. There, six molecules of oxygen react with one molecule of glucose to form six molecules of water and six molecules of carbon dioxide (the waste products of the reaction).