Energy storage and reuse in biological systems: Case studies

Abstract

The consequences of energy storage in the body as fat and then reusing it in the metabolism are assessed for seven cases by referring to entropy generation as the criterion for assessment: Case 1: Glycogen and lipids are stored by a person by dieting and then reused. Case 2: Glucose is converted into fat and then reconverted it into glucose spontaneously. Case 3: 2400 kcal of high-fat diet induced fatty liver disease and then a low-fat diet is consumed to recover. Case 4: Intermittent fasting by skipping a meal up to 30 days/year. Case 5: Salmon store fat in its body and reuse it later during its journey back to its spawning place. Case 6: Entropic assessment of the female arctic squirrels in hibernation is done. Case 7: Mean exergy cost of active field metabolism of homeothermic/ endothermic birds and mammals is compared. Assessments show that energy storage and its reuse generated negligible aging entropy in humans, intermittent caloric restriction via skipping a meal for 30 days in a year may extend the life span approximately 3%. Migrant or hibernating animals store energy and then reuse it with absolutely different purposes than the humans and generate most of their life span entropy.

Species‐specific biological energy storage and reuse

“…During cold exposure, an 80.7 kg healthy man metabolizes 0.0016 mol/24 hours glucose depending on BAT activity. The amount of heat may be calculated by using Equation (2).…”

“…If an organism cannot get sufficient energy to survive, and export entropy it will cease to exist. 1 Assessing energy utilization and storage and entropy generation 2 behavior may indicate the differences between healthy and unhealthy organisms and offer remedies to treat the morbidities. [3][4][5][6] In the present study, species-specific biological energy storage and reuse will be evaluated.…”

Thermodynamic Assessment of the Impact of Pregnancy and Lactation on the Longevity of Women

“…The results of this study should be interpreted with caution, in case of sarcopenia or famine human body may consume its own building blocks in its energy metabolism and such an experience do not extend the lifespan. On the other hand, Ulu et al [59] showed that intermittent caloric restriction via skipping a meal for 30 days in a year without increasing the caloric content of other meals might extend the life span approximately 3%. A high-entropy generation process shortens the expected longevity more than a low-entropy generation process, as evidenced in Table 5.…”

Diet-dependent entropic assessment of athletes’ lifespan

“…Energy, e.g., enthalpy, extracted from carbohydrates will not be affected by lactic acid accumulation and its reuse in the muscles, since enthalpy is a state function and its value depends on the initial, carbohydrates and the oxygen, and the final chemical species, e.g., carbon dioxide and water ( 45 ) . Ulu et al ( 46 ) , while discussing energy storage and reuse in biological systems, reported that entropy generation associated with this phenomenon is extremely small and does not contribute to the lifespan entropy accumulation; therefore, entropy generation during lactic acid utilisation and reuse in the muscles is neglected.…”