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2 What’s an Enzyme? 1.Enzymes are __________. 2.Enzymes are ___________. Catalysts _________ chemical reactions End in –____ (Ex: sucrase, catalase) Without an enzyme! With an enzyme!

3 WARNING Superman had Kryptonite Enzymes have 1.______________(pH) 2.______ Temperatures 3.Extreme _____Temps

4 Chemical Reactions ___________ → (yield) _________ Ex: Fe + O 2 → rust

Energy-______________ReactionEnergy-_____________ Reaction Products Activation energy Activation energy Reactants There are 2 kinds of chemical reactions ____________ ___________ _____________ ___________

All chemical reactions require a certain amount of energy to get started. - This is called the… _____________ __________ 6

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8 Why do we need Enzymes? Speed up rate of chemical reaction by __________ the ____________ energy (energy needed to start chemical reaction) _________ enzyme ____________ _______ enzyme _________ energy without enzyme __________ Energy with enzyme _____________

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11 How do ENZYMES work? 1.The enzyme attaches to ___________ 2.The reactants that bind to the enzyme are known as the ___________. 3.The part of the enzyme where the substrate attaches to the enzyme is called the _________________. 4.The shape of the active site only ____ the shape of the substrate, like a _____ fits a ____. Only the correct substrate binds to the enzyme.

12 Reactants/ Substrates Enzyme Lock-and-Key Mechanism- Enzymes can only bind to certain _________

13 How do you speed up enzymes? 1.Add ______ of the enzyme. 2.________ up the enzyme! Don’t warm it too much or it may not work anymore

14 Once the enzyme and substrate are together, the enzyme holds the substrate so the _______ can occur. Once the reaction is over, the enzyme _________ the product and the enzyme can start a _______ reaction with an identical substrate. Enzymes are ___ permanently changed or used up in reactions

15 A change in the ____ of the enzyme can cause a change in the _________ of the active site, therefore changing the activity of the enzyme.

16 What Affects Enzyme Activity? Three factors:Three factors: 1.______________Conditions 2.__________and _________ 3.Enzyme ____________

17 1. Environmental Conditions 1. Extreme ___________are the most dangerous 1. Extreme ___________are the most dangerous - high temps _________(unfold) enzyme. - high temps may _________(unfold) the enzyme....Let's see......Let's see... 2.pH (most like _____pH near _____) 3._______ concentration (salt ions)

18 2. Cofactors and Coenzymes Inorganic substances (_______, ______) _________ enzymatic ___________ Inorganic substances (_______, ______) and _________ (respectively) are sometimes needed for proper enzymatic ___________. –Example: Iron__________(a protein in red blood cells) pick up ___________. Iron must be present in the __________(a protein in red blood cells) in order for it to pick up ___________. ___________ enzyme helpers (inorganic) __________ cofactors

19 Two examples of Enzyme Inhibitors a. ___________ __________: resembleenzyme’s normal _______compete _______site a. ___________ __________: are chemicals that resemble an enzyme’s normal _______and compete with it for the _______site. Enzyme Competitive inhibitor Substrate

20 Inhibitors b.____________inhibitors: do not enter the _____ sitebind to _______ part enzymeenzyme ______ its _______ alters the active site Inhibitors that do not enter the _____ site, but bind to _______ part of the enzyme causing the enzyme to ______ its _______, which in turn alters the active site. Enzyme active site altered Noncompetitive Inhibitor Substrate