Final answer:
Glycolysis produces pyruvate, which can feed into the Krebs cycle, electron transport chain, and fermentation. Pyruvate's use in these processes depends on the presence of oxygen. The products include ATP and other high-energy molecules, making option d (all of the choices) the correct answer.
Step-by-step explanation:
Glycolysis makes products that feed into the Krebs cycle, the electron transport chain, and fermentation processes. After glycolysis, pyruvate is produced, which can be further used in different ways depending on the availability of oxygen. If oxygen is present, pyruvate enters the mitochondria, where it is converted to acetyl-CoA and begins the Krebs cycle. The Krebs cycle generates high-energy molecules such as ATP, NADH, and FADH2. NADH and FADH2 then donate electrons to the electron transport chain to generate a proton gradient that helps produce even more ATP through oxidative phosphorylation. If oxygen is not present, pyruvate is used in different types of fermentation to regenerate NAD+, which is essential for the continuation of glycolysis, while also producing other by-products like ethanol or lactic acid.