1. CELLULAR ENERGTICS CHAPTER 6

2. ENERGY THE ABILITY TO DO WORK *energy is measured in joules and/or calories *1 cal= 4.18 J

3. Thermodynamics:  Study of energy and its transformations/changes

4. 2 types of systems:  Closed system: doesn’t exchange energy from surroundings  Open system: can exchange energy from surroundings

5. 1 st Law of Thermodynamics  Energy cannot be created nor destroyed only transferred (reaffirms the law of conservation of energy)

7. 2 nd Law of Thermodynamics  When energy is converted from one form to another, some usable energy is converted into heat that is “lost” into the atmosphere

8. Chem notesheet  9b) Heat flows from HOT to COLD. This law is sometimes stated in terms of ENTROPY (disorder).  Entropy is the UNAVAILABILITY of energy.  The Second Law of Thermodynamics says used energy cannot be retrieved without additional ENERGY.

9.  Machines never work over 100%

10. ENTROPY  Measure of disorder/randomness  Sometimes this is used to explain the 2 nd Law of Thermodynamics

13. Enthalpy  Total PE of a system

14. For Chem:  Think of ENTHALPY as the heat content of a substance….a natural system tends to go from a state of high energy to one of low energy  Ex. A ball rolls downhill, not uphill…  ENTROPY: disorder…nature processes tend to go from orderly to disorderly

15. FREE ENERGY  Amt of energy available to do work (G)  H = G + TS H=enthalpy G=free energy T=absolute temp S=entropy

16. Exergonic reactions  Release energy  Free energy decreases during exergonic rxns

17.  Energy, Enthalpy and the First Law of Thermodynamics Energy, Enthalpy and the First Law of Thermodynamics

19. Endergonic reaction  Gain of free energy  Energy goes “in”  Net gain: Free energy increases