(a) explain how the process of how fat storage in her body can be used to generate energy?

Question

During an extended period of physical activity, an athlete is able to metabolize all the energy consumed in her breakfast that consisted mainly of carbohydrates. However, once glucose is no longer available, (a) explain how the process of how fat storage in her body can be used to generate energy? (b) As she gasps to catch her breath, not enough oxygen is entering her body. Explain how the accumulated acid from fermentation can be used to produce energy once oxygen is available again?

Answer 1

a) The fat storage in the athlete's body can be used to generate energy after the glucose supply is depleted. Body fat is stored as triglycerides, a type of lipid that can be described as a glycerol molecule bound to three fatty acids. When glucose is completely depleted, enzymes in the athletes body can digest triglycerides into free fatty acids and glycerol. The fatty acids are then taken up by cells by fatty acid transporters, and are metabolized through a process called beta-oxidation, which transforms fatty acid acyl CoA into Acetyl CoA, which is then further stripped of carbons during the normal cellular respiration process in the mitochondria.

b) The accumulated acid from fermentation can be used to produce energy once oxygen is available again through a similar process as outlined above. Lactic acid is produced from the anaerobic digestion of glucose, which splits the molecule into two pyruvate molecules, releasing about 2 ATP molecules. The pyruvate, because there is no oxygen available, cannot be further broken down, and consequently accepts two electrons from 2NADH+, forming lactic acid. This formation is temporary. After oxygen is again available , the lactic acid can be reformed into pyruvate by the removal of electrons and can then be metabolized by the mitochondria during aerobic cellular respiration.