Glycolysis is the stage where glucose is broken down into 2 pyruvates (3 carbon compounds). This occurs in the cytoplasm and produces 2 ATP molecules. The pyruvates enters the mitochondria and enters the link reactions where it combines with co enzyme A (CoA). Decarboxylation ( removal of CO2) and dehydrogenation (removal of H) occurs here. Since CO2 is removed from the pyruvate it means a carbon is removed. This produces a 2 carbon compounds called acetyl. The acetyl compound is what combines with the CoA to form a compound called acetylCoA. This compound then enters the Krebs cycle.
The CoA co enzyme leaves and the acetyl reacts with a four carbon compound called oxaloacetate. This then forms a 6 carbon compound compound called citrate. A series of dehydrogenation and decarboxylation reactions occur to convert the 6 carbon compound back to oxalaoactate( the 4 carbon sugar). An ATP molecule is formed during one spin of the Krebs cycle.
The electron transport chain is where the reduced NAD (formed from dehydrogenation in glycolyisis, the link reactions and Krebs cycle) and Reduced FAD ( formed from dehydrogenation in the krebs cycle). molecules pass along a series of electrom carriers where they release energy that will be used to make ATP. Oxygen is the last electron carriers
I tried to sum it up as best as possible. If you want in detail explanations of each then I can explain it also.
