Lecture 4- Readings
Energy and Enzymes
Thursday January 17, 2013
Energy and the Laws of Thermodynamics:
- Energy cannot be measure or weighed directly.
- Can only detect it by its ability to do work.
Energy exists in different forms and states:
- Heat, chemical, electrical, mechanical
- They can all be converted or transformed readily form one form to another
- Kinetic Energy: energy possessed by an object because its in motion.
- Potential Energy: stored energy, the energy an object has because of its
location or chemical structure.
The laws of thermodynamics describe energy and its transformation:
- System: object being studied
- Surroundings: everything outside of the system
- Universe: system and surroundings
- Isolated system: does not exchange matter or energy with surroundings
- Open system: both energy and matter can move freely between system and
- Closed system: can exchange energy but no matter
The first law of thermodynamics: Energy can be transformed but not created or
- Principle of conservation of energy
The second law of thermodynamics: energy transformations increase disorder
- each time energy is transformed from one form to another, some of the
energy is lost and unavailable to do work.
- A lot of energy is lost as heat (energy associated with random molecular