The calcium ion passes easily through the membrane of one cell but cannot cross the
membrane of a second cell. which part of the plasma membrane allows this substance
to cross?
a.) carbohydrate groups on the membrane allow the ions to cross.
b.) the fatty acid tails of the phospholipids allow the ions to cross.
c.) protein channels in the plasma membrane allow the ions to cross.
d.) phosphate groups of the phospholipid bilayer allow the ions to cross.

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.

Life, yes life it self madden

Ican try, but i’m gonna need some info.