1. Energy Part 1-

2. Know these terms:  Potential energy  Kinetic energy  Metabolism  Anabolic rxn.  Catabolic rxn.  Exergonic  Endergonic

3. Kinetic energy is energy associated with motion Heat (thermal energy) is kinetic energy associated with random movement of atoms or molecules Potential energy is energy that matter possesses because of its location or structure Chemical energy is potential energy available for release in a chemical reaction Energy can be converted from one form to another Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

4. Biological Order and Disorder Cells create ordered structures from less ordered materials Organisms also replace ordered forms of matter and energy with less ordered forms Energy flows into an ecosystem in the form of light and exits in the form of heat Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

5. Laws of Thermodynamics 1 st - Energy is neither created or destroyed. Any conversion of energy, the total energy before and after is the same. – (think energy pyramid) 2 nd - when energy is converted from one form to another some of that E becomes unavailable for doing work. Lost to disorder – Entropy is a measure of the disorder in a system

6. (a) First law of thermodynamics (b) Second law of thermodynamics Chemical energy Heat CO 2 H2OH2O +

7. In any system: Total E = Usable E + Unusable E Enthalpy (H) = Free E (G) + Entropy (S) (T) Or Free E (G) + Enthalpy (H) – Entropy (S) (T) usable total unusable

8. 2 nd Law of Thermodynamics G = G products – G reactants If G is negative, free energy is released, exergonic Complex molecules > smaller molecules + free E If G is positive, free energy is consumed, endergonic Small molecules + E > complex molecules What happens if no free energy is available?

10. Energy and Energy Conversions Negative change in free energy ( G) Kinetic Energy Positive change in free energy ( G) Potential Energy Catabolic Exergonic Releases Anabolic Endergonic Stores

12. ATP: Transferring Energy to the Cells Lifewi re 8.1

13. ATP drives endergonic reactions by phosphorylation, transferring a phosphate group to some other molecule, such as a reactant The recipient molecule is now phosphorylated Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

14. How ATP Performs Work The three types of cellular work (mechanical, transport, and chemical) are powered by the hydrolysis of ATP In the cell, the energy from the exergonic reaction of ATP hydrolysis can be used to drive an endergonic reaction Overall, the coupled reactions are exergonic Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

15. How to remember … G< 0 spontaneous- exergonic- energy released. G>0 non-spontaneous- endergonic-energy required G=0 equilibrium

16. Glucose (O 2 ) is exergonic, H has potential energy G= -686kcal/mol

17. Coupled Reactions A reaction sequence in which energy from an energy-releasing process is used to drive an energy requiring process. http://bcs.whfreeman.com/thelifewire9e/defa ult.asp#542578__591230__ http://bcs.whfreeman.com/thelifewire9e/defa ult.asp#542578__591230__

18. Enzyme reactions at max rate

19. Irreversible inhibition Covalent binding to side chain Permanent deactivation DIPF- ir.in. of aceltylcholinesterase nerve gas insecticide malathion Not common in cells Cells prefer reversible inhibition

20. Reversible inhibition Competitive inhibitor, fits active site, similar to substrate. Competes. Non-competitive inhibitor, binds at distant site shape change to active site. allostery (different shape) Allosteric enzymes- usually quaternary, multiple subunits, sigmoid appearance graph.

21. Feedback inhibition

22. Enzyme action A series of enzymes catalyze the reaction X -- Y -- Z -- A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as? Substance X functions as? a. a coenzyme. b. an allosteric inhibitor. c. the substrate. d. an intermediate. e. a competitive inhibitor.