How can we study medical from beginner ? and which book is good ?

I'm not sure what you are directly asking, but I take it you are wanting to become a medical student? Well, I would recommend starting with medical terminology so you can familiarize yourself with the terms. It is hard to recommend any books unless you have a specific category you are looking to study. You would have to choose a certain medical area, such as cardiovascular, pulmonary, ect. before you could get recommendations. Hope I helped a little!!

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.

Carbon dioxide is the correct answer