What is the adp-atp cycle and how does it apply to our daily life of eating 3 square meals a day?

ATP (adenosi triphosphate) is the energy used by the body for all its functions, which we obtain from food. That ATP, upon losing a phosphate, becomes ADP Adenosine diphosphate, hydrolyzes and energy is obtained. The ATP molecule has more energy since it has one more phosphate group.

Explanation:

Adenosine triphosphate (ATP) is a molecule that is found in all living things and is the main source of energy usable by cells to perform their activities. ATP is caused by the metabolism of food in special organelles in the cell called mitochondria. ATP behaves like a coenzyme, since its function of energy exchange and the catalytic function (stimulation work) of enzymes are closely related. The adenosine part of the molecule consists of adenine, a compound that contains nitrogen (also one of the main components of the genes) and ribose, a five-carbon sugar. Each unit of the three phosphates (triphosphate) that the molecule has, is formed by a phosphorus atom and four oxygen and the whole is attached to the ribose through one of the latter. The two bridges between the phosphate groups are high energy bonds, that is, they are relatively weak and when the enzymes break them they give up their energy easily. With the release of the phosphate group at the end, seven kilocalories (or calories in common language) of energy available for work are obtained and the ATP molecule becomes ADP (adenosine diphosphate). Most energy-consuming cellular reactions are enhanced by the conversion of ATP to ADP including the transmission of nerve signals, muscle movement, protein synthesis and cell division. In general, ADP quickly recovers the third phosphate unit through the cytochrome reaction, a protein that is synthesized using the energy provided by food. In vertebrate muscle and brain cells, excess ATP can bind to creatine, providing a reservoir of reserve energy.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.