When glucose is broken down, there is an accompanying release of energy. How do organisms use this energy? Or, better yet, why do they even need energy? These not so trivial questions require an understanding of some important general laws that govern energy utilization.
Energy I Part 1 VoiceThread Transcript
Thermodynamicsis the physics of energy transformations that occur in a collection of matter. Formally, any collection of matter under thermodynamic scrutiny is defined as a "system." Bioenergetics is the area of thermodynamics that deals specifically with the energetic reactions that occur in an organism; energetically, an organism is a "system." There are a few laws that apply to energy (both biological and nonbiological). The laws of thermodynamics are actually quite simple, but have some far-reaching implications (not only to life, but to all interactions between energy and matter).
Thefirst law of thermodynamicsstates that energy is neither created nor destroyed. In other words, the amount of energy in the universe is constant. This concept is straightforward but can be confusing. You might have heard someone say that plants "make energy from the sun." Plants actually convert solar energy (sunlight) into molecular potential energy, in the form of sugar. Remember, plants do not "make" energy. Photosynthesis converts light energy (a form of kinetic energy) into chemical energy. This first law could be considered "bookkeeping." It states that the energy used and released in any reaction must be balanced. Note that the energy in one molecule can be distributed into two or more other molecules.