Oxygen gas (O2) drives cellular respiration, the process by which animals release the chemical potential energy stored in food, producing carbon dioxide (CO2) as a byproduct.
ˈɑːksɪdʒən ɡˈæs ˈoʊ tˈuː dɹˈaɪvz sˈɛljʊlɚ ɹˌɛspᵻɹˈeɪʃən, ðə pɹˈɑːsɛs baɪ wˌɪtʃ ˈænɪməlz ɹᵻlˈiːs ðə kˈɛmɪkəl pətˈɛnʃəl ˈɛnɚdʒi stˈoːɹd ɪn fˈuːd, pɹədˈuːsɪŋ kˈɑːɹbən daɪˈɑːksaɪd sˌiːˈoʊ tˈuː æz ɐ bˈaɪpɹədˌʌkt.