1. Chapter 8 THE ENERGY OF LIFE

3.  Energy is neither created nor destroyed  Entropy increases throughout time LAWS OF THERMODYNAMICS

4.  Biological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis. THE ENERGY OF LIFE

5. FREE ENERGY

7.  Enzymes facilitate metabolic pathways FREE ENERGY

8. Chapter 8 ENZYMES

9.  Non biological reactions use heat as a catalyst  Biological reactions use enzymes  Enzymes: Speed up reactions  Heat would trigger all reactions in a cell  Destroy macromolecules ENZYMES

10.  The most structurally sophisticated molecules ENZYMES ARE PROTEINS

11.  Metabolic reactions are usually not spontaneous  Initial investment of energy to start a reaction  Enzymes lower the Ea of a reaction START THE REACTION

12.  Every enzymes is substrate specific!  Induced Fit: enzyme changes shape  Substrate is broken down or built up MIDDLE OF THE REACTION Hexokinase (a) without (b) with glucose substrate http://www.biochem.arizona.edu/classes/bioc462/462a/NOTES/ENZYMES/enzym e_mechanism.html

13.  Enzymes are not used up in the reaction END THE REACTION

14.  Amylase:  in your mouth breaks down sugar  Peptidase  in your stomach break down proteins  Lipase:  in your small intestine break down lipids  ~2000 enzymes in your body working right now!!! COMMON ENZYMES IN YOUR BODY

15. REGULATING ENZYMES

16.  Heat: Denatures enzymes  pH: Acids or bases denature enzymes ENVIRONMENTAL EFFECTS

17. HEAT

18. PH

19.  Competitive  Similar in shape and attach to active site disabling the enzyme  Noncompetitive  Bind to allosteric site of the enzyme altering the shape of the active site INHIBITORS

20.  Nonprotein helpers for enzyme-substrate complex COFACTORS

21.  The product of a metabolic pathway may bind to the allosteric site and turn off the enzyme FEEDBACK INHIBITION