Energy is really important because we need it to reproduce, synthesis, to move, to grow, and to regulate our temperature.
The work of life is done by energy coupling, which is using exergonic reactions to fuel the endergonic reactions.
Whatever we eat, we have to digest or break it down to simpler molecules that can enter our cells and they can eventually use them. We need something in our body which helps to pass this energy around. And the best answer is ATP!!!.
ATP stands for Adenosine Triphospate. Where do we see Adenine before? In RNA and DNA.
ATP has three phosphate group attaches to an adenine and ribose.
First we start out with adenosine, and ribose, and when we attach one phosphate to this, this is named AMP or adenosine monophosphate, which means one phospate.
Then when we add another phosphate group to the adenine, ribose, and previous phosphate group, we make adenosine diphosphate, meaning two phosphates.
Third, we make ATP by adding another phosphate group, thus making adenine triphosphate.
Adding all these phosphates requires A LOT of energy and I mean A LOT.
BUT, the question is why does it require so much energy? Well lets see an example, remember when we hold magnets together towards the same poles, WHAT DO THEY DO? THEY REPEL EACH OTHER. This is the same reason for the phosphates. The phosphates are highly negative and do not want to be with another molecule which is also highly negative. This is due to the oxygen. AND WHAT IS OXYGEN? HIGHLY ELECTRONEGATIVE.
The phosphate bonds make ATP an excellent energy donor.
HOW DOES ATP TRANSFER ENERGY?
The word is PHOSPHORYLATION. This is when phosphate is taken off of ATP. This released phosphate can be transferred to other molecules. And enzyme that helps in this is kinase.
Building polymers from monomer is a perfect example of phosphorylation. The bonds holding the monomer have to be destabilized in order to make it a polymer.
The first step of cellular respiration is glycolysis. This is the breaking of glucose to make ATP. First the bonds of glucose have to be destabilized in order for it to be broken down. And whenever a carbon to carbon bond is broken, energy is released!!