In: Biology
Excess food is stored in our body either in the form of carbohydrates (in the muscles and liver) or as fat (adipose tissue). When our body needs additional energy it uses the carbohydrate source first as a source of “quick” energy, then the fat. Why do you think carbohydrates are used as a source of quick energy rather than fat?
Carbohydates are quick source of energy. It can provide energy both in the presence or in the absence of oxygen. Whereas fat can provide energy only in presence of oxygen. Energy storage capacity is different for carbohydrates and lipids. Each gram of carbs store 4 calories while lipid store 9calories per gram. This makes lipid a stored form of energy. Therefore carbs act as immediate energy source and body use fat as energy source when the glucose storage depletes.
Carbohydrates are stored in limited quantity because they act as immediate energy source. Carbohydrates are digested as glucose or other simple sugars that are absorbed directly into the intestine and move through circulation into different cells. The liver store excess glucose once it passes through circulation. This stored glucose will be distributed in between meals. The glucose is stored as fat if level if beyond that liver can’t hold. Thus when carbohydrates are scarce then only body uses fat.
Some cells like brain cell can only use carbohydrates as energy source.
Carbohydrates are brokendown for energy by glycolysis, citric acid cycle and the electron transport chain. The chemical composition of carbs that are made of C,H and O makes if easy for decomposition than fat.