Ch. 6 Summary

# Ch 6 Summary - Chapter 6 Energy and Metabolism Define energy emphasizing how it is related to work and heat Energy is the capacity to do

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Chapter 6: Energy and Metabolism Define energy, emphasizing how it is related to work and heat: Energy  is the capacity to do work (expressed in  kilojoules, KJ ). Energy can be conveniently measured as  heat energy , thermal energy that flows from an object  with a higher temperature to an object with a lower temperature; the unit of heat energy is the  kilocalorie (kcal) , which is equal to 4.184 kilojoules. Heat energy cannot do cell work. Use examples to contrast potential energy and kinetic energy: Potential energy  is stored energy;  Kinetic energy  is energy of motion. All life depends on a continuous input of energy. All forms of energy are interconvertible. For  example, photosynthetic organisms capture radiant energy and convert some of it to  chemical  energy , a form of potential energy that powers many life processes. State the first and second laws of thermodynamics, and discuss the implications of these  laws as they relate to organisms: closed system  does not exchange energy with its surroundings. Organisms are  open  systems . The  first law of thermodynamics  states that energy cannot be created or destroyed but can be  transferred and changed in form. The first law explains why organisms cannot produce energy,  but as open systems they continuously capture it from the surroundings. The  second law of thermodynamics  states that disorder (entropy) in the universe, a closed  system, is continuously increasing. No energy transfer is 100% efficient; some energy is  dissipated as  heat , random motion that contributes to

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## This note was uploaded on 04/30/2008 for the course BIO 101 taught by Professor Wetherbee during the Fall '08 term at Rhode Island.

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Ch 6 Summary - Chapter 6 Energy and Metabolism Define energy emphasizing how it is related to work and heat Energy is the capacity to do

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