The human body uses the breakdown of macronutrients to obtain energy. the nutrients must be converted to ( which is the form of energy used by the cells. cells can obtain this form of energy from all of the macronutrients if the cells have enough ( the part of the cell that most energy metabolism takes place. if the cells lack this organelle, they need a supply of glucose to provide energy to the cell through a process called glycolysis. if the diet is adequate in all 3 of the macronutrients, the macronutrient used by most cells for energy is ( which have been broken down to monosaccharides, the main one being ( which can be obtained from the diet (through the digestion and absorption of food) or broken down from glycogen stores, a process known as ( if the diet is lacking in adequate amounts of carbohydrates, the body can convert amino acids and glycerol to glucose by a process called ( in order for the cells to obtain energy from glucose, it must first be converted to pyruvate through a series of reactions called ( which happens in the cytosol of the cell. if adequate oxygen is not available (such as in working muscles) pyruvate is converted to ( and sent to the liver where it is converted back to glucose and sent back to the muscle in a cycle called the ( triglycerides are also a significant source of atp. they are derived from the diet (through the digestion and absorption of food) or broken down from body fat (adipocytes) stores, a process known as ( the glycerol backbone can be converted to pyruvate (then back to glucose, a process called gluconeogenesis, or to on to acetyl coa). the fatty acid chains are broken down to acetyl coa in a process known as ( this can then be concerted to atp, or if the cells have adequate energy the body can use this pathway and the acetyl coa can be converted to triglycerides/ body fat through a process known as ( amino acids are used by the body for building and repairing but can also be used as a source of energy if needed. they are derived from the diet (through the digestion and absorption of food) or broken down from muscles, a process known as ( the first step in amino acid metabolism is ( when the amino group is removed from the amino acid and converted to ammonia then to urea and excreted. the remaining keto acids can then be converted to pyruvate. the 1st step of the ( cycle is for coa to be removed from ( to join with oxaloacetate to form ( during the 8 reactions that take place, for every 1 molecule of acetyl-coa the cycle produces 3 nadh and 1 fadh2 along with 1 molecule of atp. nad & fad are examples of ( which are organic molecules that function as enzyme and are derived from b vitamins and assist by accepting & donating hydrogen ions (h+) & electrons (e-) during reactions. the hydrogen & electrons collected during energy metabolism are shunted to the inner membrane of the mitochondria. the ( of 4 complexes on the inner membrane. energy is releases as the electrons go from a higher to a lower state and this energy is used to pump hydrogen ions (h+) from the inner matrix to the outer membrane where they build up creating an electrochemical gradient. this gradient ‘forces' hydrogen ions (h+) to flow from back from the outer membrane into the inner matrix through specialized channels. the flow of h+ through the channels drives ( causing the creating of atp.