Question

What is ATP and what is its importance in living beings?

Answer 1

Hint: Adenosine triphosphate, or ATP, is a molecule which acts as the primary carrier of energy in cells. When food molecules in the cell break down, certain chemical energy is released. This energy is released which is captured by ATP. ATP releases these energies to fuel other cellular processes. Thus, ATP acts as a mediator between the different processes of the cell.

Complete answer:
Every living being's cell has three main functions for which chemical energy is required: to drive metabolic reactions that do not occur automatically; to transport necessary substances across membranes; and to perform mechanical work, such as moving muscles. When any of these functions are to be executed (which happens every moment that we are alive), the energy from storage molecules is converted to ATP; and ATP shuttles between the locations where energy consuming activities are being performed.
ATP is, basically, a nucleotide bound to three phosphate groups. The nucleotide is adenosine. A nucleotide consists of the nitrogenous base, adenine; the sugar, ribose; and a chain of three phosphate groups bond to ribose. The three phosphate groups are named as alpha, beta and gamma, with respect to their distance from the ribose sugar. The actual power source which the cell taps is the phosphate of ATP. The beta and gamma bonds of phosphates release energy when they are broken. The phosphate bonds are broken by consuming a water molecule (a process called hydrolysis). Usually, the outer phosphate is removed and transferred to another molecule by a process called phosphorylation. The removal of the outer phosphate group is carried out by special enzymes. Simultaneous breaking and synthesis of ATP molecules happen through the process of cellular respiration. Enzyme ATP synthase produces most of the ATP by converting adenosine diphosphate and phosphate into ATP. This enzyme, ATP synthase, is located in the mitochondria; and in chloroplasts in plants.
Formula of ATP: $C_{10}{H}_{16}{N}_5{O}_{13}{P}_3$
Molar mass: 507.18 g/mol
ATP hydrolysis: $ATP+H_{2}O\to ADP+Pi$+ free energy [where, Pi is the inorganic phosphate and ADP adenosine diphosphate]

Note:
ATP, discovered in 1929, is referred to as the “molecular unit of currency” of intracellular energy transfer. During various metabolic processes, ATP is converted into either ADP (adenosine diphosphate) or AMP (adenosine monophosphate). The regeneration of ATP also takes place so that the human body recycles its own body weight equivalent in ATP every day. The following biochemical functions are performed by ATP: intracellular signaling, DNA and RNA synthesis, amino acid activation in protein synthesis, ATP binding cassette transporter, extracellular signaling and neurotransmission and protein solubility.

Figure: ATP