Question

In what process do animals use glucose and oxygen?

Answer 1

Animals and all life that requires oxygen to survive, use glucose and oxygen in aerobic cellular respiration. Aerobic cellular respiration breaks down glucose molecules, storing the energy released during the process in molecules of ATP (adenosine triphosphate), which provide the energy needed for cell(s) to do work.

Aerobic cellular respiration can produce 36 to 38 molecules of ATP from one glucose molecule, whereas anaerobic respiration (glycolysis followed by fermentation) produces a net gain of only 2 molecules of ATP from one glucose molecule.

Aerobic respiration consists of three stages: glycolysis, which occurs in the cytoplasm; and the Krebs cycle and electron transport chain, which occur in the mitochondria. The majority of the ATP is produced during the electron transport chain.

Oxygen is the last electron acceptor in the electron transport chain, and combines with electrons and `"H"^+"` ions, to form water, which is removed. A new oxygen molecule takes the place of the one that combined with hydrogen ions and electrons to form water, and the electron transport chain continues. Without oxygen, the hydrogen ions and electrons will have nowhere to go, the electron transport chain will back up, aerobic respiration will stop, most of the ATP will not be produced, resulting in death for organisms that cannot switch to anaerobic respiration to a sufficient degree to sustain life.

The overall chemical equation describing aerobic respiration is:

`"C"_6"H"_12"O"_6"` + `"6O"_2` `rarr` `"6H"_2"O"` + `"6CO"_2"`

The basic process of aerobic respiration is: