All living cells require energy to carry out various cellular activities. This energy is stored in the chemical bonds of organic molecules (e.g. carbohydrates, fats, proteins) that we eat as food. These organic molecules are broken down by enzymatic reactions in cells to generate energy in the form of adenosine triphosphate (ATP). The ATP generated by these pathways in cells is used to drive fundamental cellular processes. The food we consume is mainly comprised of proteins, polysaccharides (carbohydrates) and fats. These are first broken down into smaller units: proteins into amino acids, polysaccharides into sugars, and fats into fatty acids and glycerol. This process of digestion occurs outside the cell. The amino acids, simple sugars and fatty acids then enter the cell and undergo oxidation by glycolysis (in the cytosol) and the citric acid cycle (in the mitochondria) to generate ATP (from ADP and Pi).
describe glycolysis, Citric Acid Cycle
explain Glycogenesis and Glycogenolysis
describe the Hormonal regulation of blood sugar level