Cellular Respiration

Abstract

Oxygen and food. They are both required for living organisms. Why must living organisms consume these resources in order to sustain life? To answer this question, we must first define what a living organism is. Two characteristics of a living organism are their ability to respire and their ability to acquire nutrition. Respiration can be defined as, “the release of energy from food substances in all living cells”. [1] Nutrition can be defined as, “the process by which organisms obtain energy and raw materials from nutrients such as proteins, carbohydrates and fats”.[2]Animals, just like humans, obtain oxygen through the physiological process of breathing and their nutrition through the food they consume. Now that we have working definitions of living organisms, respiration, and nutrition, we know partly what the purpose of consuming these resources is for. But, what about energy? What are the roles of these resources in the production and consumption of energy? Whether it be a human riding a bicycle or an Alaskan sled dog running a 1,000-mile Iditarod race, energy is required to successfully complete these activities. In order to make the energy needed for these activities, oxygen and food must work together as a team to convert the biochemical energy found in food into the “energy currency” molecule, adenosine triphosphate (ATP), by a process called cellular respiration. An important molecule extracted from food and used as a fuel for the cellular respiration process is the sugar called glucose.