• sparkyshocks@lemmy.zip
        link
        fedilink
        English
        arrow-up
        7
        ·
        17 hours ago

        That’s true of the metabolic pathways for fat, protein, and alcohol, too. Each oxygen molecule we breathe feeds into chemical reactions so that it picks up a carbon atom and becomes CO2 on the way out. The carbon comes from whatever food was metabolized, including anaerobic respiration where the lactic acid eventually gets cleared out.