Cellular Respiration and Combustion

Cellular Respiration and Combustion!

Cellular respiration is primarily an energy-yielding dissimilation process and a phenomenon exhibited by all living organisms (plants, animals and microorganisms).

In this process high energy containing substances, generally carbohydrates (starch, glycogen, sucrose, glucose) or proteins or lipids are broken down into a stepwise manner, under enzymatic control, into simpler substances of lower energy content. Energy is liberated at certain specific states in the form of high energy phosphate (~ P) which are trapped in ADP (Adenosine diphosphate) and stored in pyrophosphate bonds of ATP (Adenosine triphosphate).

Respiration (aerobic) is usually represented by the following equation:

Respiration is defined as follows:

Cellular respiration is a process of biological oxidation of food materials (respiratory substrates or fuel molecules) in a cell, using molecular O₂, producing CO₂ and H₂O, and releasing energy in small steps and storing it in biologically useful forms, generally ATP (adenosine triphosphate).

Respiratory substrates may be carbohydrates, fats, proteins and organic acids.

Cellular Respiration and Burning (Combustion):

Cellular respiration resembles ordinary combustion or burning in the breakdown of chemical bonds, use of oxygen, production of carbon dioxide, and release of energy, but there are some fundamental differences between the two processes.

Combustion releases a large amount of energy in a single step, and most of it changes into heat and some at times into light, and raising the temperature greatly. Cellular respiration releases energy in steps, and each energy releasing step is coupled with the synthesis of ATP. Only a small amount of energy dissipates as heat. Respiration may be called as “slow burning”.