anabolic takes up energy / captured in the chemical bonds that are created - smaller molecules into bigger molecules

catabolic releases energy / break down larger molecules into smaller ones , in a biological system _the energy released may be used in new chemical bonds or in kinetic energy

thermodynamics difference in temperature

• first law of thermodynamics is that energy is neither created nor destroyed
• second law, no physical process or chemical reaction is 100% efficient / applied to all energy systems*

entropy is a measure of the disorder in a system

• unless energy is applied to a system, it will be randomly arranged or disordered

total energy = usable energy + unusable energy

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• enthalpy (H) total energy
• free energy (G) _is what is required by cells for growth, cell division, and maintenance

H = G + TS

• enthalpy= free energy + temperature(entropy)

for usable energy;

• G = H - TS

we can determine the change in each at a constant temp;

• calories (cal) / joules (J)

a change is represented by delta (△)

• the change in free energy (△G) of any chemical reaction is equal to the difference in free energy between products and reactants
  • △G reaction = G products - G reactants
• if the products have more free energy than the reactants (△G is positive), then there must have been some input of energy into the reaction.

at a constant temperature △G is defined in terms of the change in total energy (△H) and the change in entropy (△S)

• △G = △H - T△S
• if △G is negative (△G < O), free energy is released
• if △G is positive (△G > 0), free energy is required
• if △G (free energy) is not available, there is NO reaction