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Biology LibreTexts

4: Bioenergetics

  • Page ID
    16435
    • 4.1: Introduction
      In living systems, we do not have to worry about the third law because equations for energy exchange in living systems already reflect the temperature dependence of entropy changes during reactions. Here we look at how we came to understand basic thermodynamic principles and how they apply to living systems. First, we will look at different kinds of energy and at how redox reactions govern the flow of energy through living things.
    • 4.2: Kinds of Energy
      We can easily recognize different kinds of energy around us like heat, light, electrical, chemical, nuclear, sound, etc., and you probably know that energy is measurable (calories, joules, volts, decibels, quanta, photons…). Even mass is a form of energy, as you may recall from Albert Einstein’s famous e=mc2 equation (the law of relativity).
    • 4.3: Deriving Simple Energy Relationships
      Consider an event, any even. I think we can agree that when stuff happens, participants in the happening go from an unstable state to a relatively more stable state. For example, you carrying a bag of marbles and you accidentally drop the bag. The marbles would fall to the floor, roll and spread out, eventually coming to a stop. At that point, the marbles are in a more stable state than they were when you were holding the bag.
    • 4.4: Key Words and Terms