The first stage glycolisis, carbon molecules are broken down into two, three carbon molecules called pryruvate. pryruvate is then sent into the mitochondria into the Krebs cycle
Krebs cycle where the carbon molecules are broken down by enzymes, ATP, and NAD+ for their electrons. Carbon dioxide is taken out as waste.
Then in the electron transport chain NADPH is used to send electrons down chain while hydrogen ions cross the inner membrane making a concentration gradient. Finally hydrogen ions are pssed through ATP synthase and combine with ADP to make ATP. The electron from the chain is then connected with hydrogen and oxygen to make water as waste.