Where is the heart located in your body?

It might be a shocker for some of you, but hearts isn't really located on the left side of your chest. It lies between the right and left lungs, in the middle of the chest and slightly towards the left of the breastbone. The heart is enclosed in the pericardium which is a double layer.

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.