1. Biochemistry Unit Workbook: pg. 61 Textbook: pg. 69

2.  http://www.sumanasinc.com/webcontent/ani mations/content/enzymes/enzymes.html http://www.sumanasinc.com/webcontent/ani mations/content/enzymes/enzymes.html

3.  Enzymes are biological catalysts that increase the speed of biochemical reactions within cells.  Enzymes are globular proteins that are NOT consumed during reactions. This means they are readily available to catalyze the same reaction over and over again.  Enzymes speed up chemical reactions by lowering the activation energy needed for the reaction to proceed. Without the presence of enzymes, biochemical reactions within the cells would not occur fast enough to sustain life.

4.  EXERGONIC REACTION:  products have a lower energy than the reactants  products have less free energy than that of the reactants and energy is given off from the system.

5.  ENDERGONIC REACTION :  Products have a higher energy than the reactants  The system requires energy  These reactions cannot occur spontaneously, energy is required to be invested in the products.

6.  The shape of an enzyme is so specific that only one type of substrate (reactant) is capable of properly binding to the enzyme. If the shape of the enzyme should change or become altered, the enzyme will be inactive and the chemical reaction will not be catalyzed.  Most enzymes end with “ase”. So if you are struggling with the name of an enzyme and you know the name of the substrate, just change the ending to “ase”. So lactase is the enzyme involved with converting lactose into glucose and galactose. Amylose is the substrate for the enzyme amylase.

7.  http://lgfl.skoool.co.uk/content/keystage3/bi ology/pc/learningsteps/PAELC/launch.html http://lgfl.skoool.co.uk/content/keystage3/bi ology/pc/learningsteps/PAELC/launch.html  Digital Experiment: http://lgfl.skoool.co.uk/content/keystage3/bi ology/pc/learningsteps/DIELC/launch.html http://lgfl.skoool.co.uk/content/keystage3/bi ology/pc/learningsteps/DIELC/launch.html Textbook: pg. 72

8.  http://lgfl.skoool.co.uk/content/keystage3/bi ology/pc/learningsteps/TAELC/launch.html http://lgfl.skoool.co.uk/content/keystage3/bi ology/pc/learningsteps/TAELC/launch.html Textbook: pg. 72

9. http://www.lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html

10.  In an enzyme catalyzed reaction, the substrate binds to a location called the active site.  A substrate-enzyme complex forms when the substrate binds to the enzyme.  The active site involves a small number of key residues that actually bind to the substrates  The rest of the protein structure is needed to maintain these residues in position

11.  Initially the active site is not a direct fit for the substrate.  As the substrate begins to interact with the amino acid side chains of the enzyme, the enzyme modifies its shape to better accommodate the substrate.  This slight change in the shape of the enzyme allows the enzyme to catalyze the reaction. Workbook : pg. 61

12.  Some enzymes require co-factors or co-enzymes to help them function properly. Co-factors are inorganic, non protein molecules that include zinc, iron, and copper. These metal ions can either bind to the active site or to the substrate to facilitate the formation of the enzyme-substrate complex.  Some of the most important coenzymes include nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+) which are involved in the process of cellular respiration and photosynthesis, respectively. These two molecules carry electrons during both reactions.

13.  There is an array of substances that can inhibit and deactivate enzyme activity by: either:  altering the active site or by  mimicking the structure of a particular substrate.  There are two types of inhibition: competitive and noncompetitive. Workbook : pg. 61 Textbook: pg. 73

14.  Compete with the substrate for the enzyme's active site.  Enter the enzyme's active site and prevent the normal substrate from binding.

15.  Attaches to a binding site on an enzyme other than the active site. http://bcs.whfreeman.com/thelifewire/content/chp06/0602001.html

16.  Cellular Respiration (text pg. 113) – negative feedback  Oxytosin and birth (text pg.336) – positive feedback http://www.northland.cc.mn.us/biology/Biology1111/animations/enzyme.html Textbook: pg. 74

17.  Cells need to regulate and control chemical reactions in order to coordinate cellular activities.  control enzyme activity by: ▪ altering the production of a particular enzyme ▪ preventing an enzyme from functioning.  Some enzymes contain allosteric sites which are receptor sites that are located far from the active site.  Allosteric activator: keeps the active site of an enzyme available to its substrate.  Allosteric inhibitor: is a substance that binds to the allosteric site and induces an inactive form of an enzyme so that the substrate cannot bind. Workbook : pg. 63

18. http://www.stolaf.edu/people/giannini/flashanimat/enzymes/allosteric.swf

21. Your Homework: