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.
Metabolism is a combination of chemical reactions that are spontaneous and release energy and chemical reactions that are non-spontaneous and require energy in order to proceed. Living organisms must take in energy via food, nutrients, or sunlight in order to carry out cellular processes.
Why is carbon important to life? Most living things on Earth are made of carbon. Living things need carbon in order to live, grow, and reproduce. Carbon is a finite resource that cycles through the Earth in many forms. This makes carbon available to living organisms and remains in balance with other chemical reactions in the atmosphere and in bodies of water like ponds and oceans.