There are two forms of metabolism: fat metabolism and protein metabolism. With fat metabolism it includes the carbohydrates, which are primarily energy foods. If there are not enough amounts of glucose to catabolize, the y will switch to the catabolism of fats for energy. Ultimately, the fats are converted into a form of glucose that will enter citric acid cycle. This will occur when a person is deprived of carbohydrates for several hours.
This is due to insulin deficiency, which is when too little glucose (sugar) enters the cells of the person with diabetes, and that is not enough for their energy needs. Ultimately, the result is that the cells will catabolize fats to make up the difference. In all individuals, fats that are not needed for catabolism are anabolized (broken down) to form triglycerides and stored in adipose (fat) tissue.
In a healthy individual, with protein metabolism, the proteins are catabolized to release energy to a minimal extent. When the fat reserves are low, which happens during the starvation associated with eating disorders (anorexia, bulimia), the body can start to use the protein molecules as their energy source. More significantly is the use of amino acids that make up proteins are broken apart to slow organic compounds that are converted to a version of glucose that will enter the citric acid cycle. When the shift relies on the protein catabolism as the major energy source, death is a possibility because of important proteins that are located in the muscles and nerves begin to catabolize.
The most common scenario in normal individuals is the protein anabolism, the action which the body builds amino acids into complex protein compounds. There are approximately 20 different kinds of amino acids. If any of those are lacking, and important proteins cannot be synthesized-this will lead to a serious health threat.
There are two forms of amino acids. Essential amino acids are the ones that have to be in the daily diet. Non-essential amino acids are those that can be missing from the daily diet because they can be made in the body.