Energy homeostasis describes the ability of all living things to sustain the stability of internal functions. Most living things require certain internal conditions to survive. A few of these factors include internal temperature, body pH, metabolic rate, and energy expended versus energy consumed. Many plants and animals, including humans, have the ability to adapt to different environments to preserve energy homeostasis. There are also several ways that humans can help their bodies remain balanced.
Under the most favorable circumstances, the amount of energy that an organism puts out will equal the amount it takes in. A simple formula to illustrate this is as follows: Energy Intake = Energy Expended + Energy Stored. This formula illustrates that every organism, when perfectly balanced, will almost immediately replace any energy expended with nourishment that then goes into storage. Perfect energy homeostasis is a never-ending cycle. Unfortunately, environmental circumstances and available nourishment don’t usually support a perfect energy cycle.
Maintaining internal energy homeostasis often requires organisms to adapt. If they don’t, they die. Reptiles, for instance, are cold-blooded, meaning they cannot regulate their own body temperatures. They must move from shade to sun to balance their internal homeostasis. Most reptiles also live in tropical, sub-tropical, or desert climates. Those placed in very cold climates cannot adapt to the sudden environmental change and perish.
Warm-blooded creatures don’t usually have this problem. They are more adaptable and can usually live in areas with changing seasons. Furry animals, for instance, grow a thick undercoat of fur and feed voraciously to put on an insulating layer of fat during cooler weather. Through these changes, their internal temperature can be maintained. Humans usually adapt through the technology of insulating clothing, fireplaces, and home heating systems. In other words, they create micro-environments to suit their needs.
Plants often maintain energy homeostasis through the amount of nutrients they choose to take in. During the spring, they absorb nutrients at a very high rate, growing very quickly to produce flowers that will later propagate their species. During the summer, they grow more slowly, concentrating energy on producing fruit. Autumn signals that plants should begin focusing energy inward. In periods of cooler weather, they maintain homeostasis through growth underground, using nutrients to expand their root systems down into warmer and nutrient-rich soils.
Nutrient intake also plays a large role in energy homeostasis. In an ideal situation, the amount of nutrients consumed would be equal to the amount of energy an organism expends. During situations where this is not possible, organisms often maintain balance by storing excess energy whenever nutrients are taken in. This generally happens when animals prepare for hibernation or when an organism cannot consume good-quality nutrients.