Where do you use oxygen that you inhale and where does the carbon dioxide come from that you exhale.

1. Why do you have to breathe? Answer this question from the standpoint of cellular respiration. Be specific with your answer. Where do you use oxygen that you inhale and where does the carbon dioxide come from that you exhale. 2. Pick three alternates to glucose based cellular respiration and describe. What are the benefits to these compared to glucose metabolism? Are there any problems with these compared to glucose metabolism?