Cold sores - painful sores on the lips and around the mouth, caused by a virus. Canker sores - painful sores in the mouth, caused by bacteria or viruses. Thrush - a yeast infection that causes white patches in your mouth. Leukoplakia - white patches of excess cell growth on the cheeks, gums or tongue, common in smokers.
Energy and Metabolism. All living organisms need energy to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is the set of life-sustaining chemical processes that enables organisms transform the chemical energy stored in molecules into energy that can be used for cellular processes.
Energy is defined as the ability to do work. Cellular respiration provides energy for living organisms. So, cellular respiration is important because it provides the energy for living organisms to perform all of the other necessary functions to maintain life. Most single-celled organisms, such as bacteria, do not require much energy and are able to survive on glycolysis and fermentation.