Proteins are primarily used for tissue repairs and synthesis. They are polymers of amino acids used to make hormones, enzymes and other chemicals of the body. Therefore proteins are only reserved for synthesis and repairs of tissues.
During extreme starvation periods when then is no source of carbohydrates and adipose tissues has been depleted/used up, proteins are alternatively used as source of energy in form of amino acids that enters the liver. Tissues such as muscles are protein degraded to provide the brain with energy in form of ketone bodies and glucose, thus the weight loss in people suffering from malnutrition.
Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the development and function of living things. All known cellular life and some viruses contain DNA. The main role of DNA in the cell is the long-term storage of information.
There are two mechanisms for energy production (glucose breakdown), aerobic and anaerobic. When adequate amounts of oxygen are present, aerobic mechanism is used. However, when there is insufficient oxygen, such as during exercise, the anaerobic mechanism is used.
