The esophagus is a tube in which food is pushed from the mouth to the stomach. as the food is pushed through the esophagus, it becomes more compact. this is-- a) physical change only

b) chemical change only

c) both physical and chemical

d) neither

help sdusdj i got c but it was wrong so now i think its a

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.

Cuz i said so. which gives it to b