3 How does the form of enzymes relate to their function?
4 Target 2.11 – Enzyme FormIn which organic class would you place enzymes? A) Carbohydrates B) Lipids C) Proteins D) Nucleic Acids
5 ENZYME FORMEnzymes are intricate, highly folded proteins made of thousands of amino acid monomers.
6 Target 2.11 – Enzyme FormWhat is name of the molecule(s) with which an enzyme reacts in a chemical reaction? A) Substrates B) Surfactants C) Competitors D) Active Sites
7 SUBSTRATESThe molecule that interacts with an enzyme in a chemical reaction is the substrate.
8 Target 2.11 – Enzyme FormIn the equation below, which substance is the substrate? A) Hydrogen Peroxide B) Catalase C) Water D) Oxygen Gas
9 CATALASE & H2O2In the decomposition of hydrogen peroxide into water and oxygen gas, hydrogen peroxide is the substrate, catalase is the enzyme and water & oxygen are the products
10 Target 2.11 – Enzyme FormIn the diagram below, what type of reaction is being catalyzed by sucrase? A) Neutralization B) Dehydration Synthesis C) Hydrolysis D) Homeostasis
11 SUCRASESucrase catalyzes the hydrolysis of the disaccharide sucrose into the monosaccharides glucose and fructose
12 Target 2.11 – Enzyme Function How does an enzyme catalyze a chemical reaction with a substrate?By buffering the addition of H+ or OH- ionsBy raising the temperature of the systemBy reducing the number of substrate molecules in the reactionBy reducing the activation energy of the reaction
13 Enzymes & EAEnzymes reduce the activation energy (EA) necessary for a chemical reaction to proceed.
14 Target 2.12 – Enzyme Specificity Where must the enzyme pair with the substrate in order for it to function properly?Functional GroupActive SiteNucleation Siteβ-Glycosidic Linkage
15 The Active SiteEnzymes pair with their substrates at the active site. Other substances may compete for access to this site, preventing chemical reactions.
16 Target 2.12 – Enzyme Specificity To what does the “lock & key hypothesis” refer?How enzymes must be unlocked by co-enzymes before they can functionHow competitive inhibitors lock out enzymes by binding to the substratesThat every enzyme reacts with two substratesThat each enzyme can only pair with one specific substrate
17 Lock and Key Hypothesis The lock and key hypothesis describes the 1:1 specificity of enzyme to substrate. Only one substrate can match the active site of any particular enzyme
19 CatecholSubstrate molecule found in the fleshy tissue of many fruits like apples, bananas, pears
20 Catechol OxidaseEnzyme that reduces the activation energy needed to oxidize catechol
21 Formation of Antimicrobial The substrate catechol combines with catechol oxidase at the active site, allowing for oxidation of catecholThe resultant product is ortho- or benzoquinone, a natural antimicrobial
22 MelaninOrtho-quinone then reacts with oxygen gas in the presence of the enzyme tyrosinase to produce melaninMelanin produces the color change to brown, similar to how your body tans when exposed to sunlight.
23 How do you prevent the production of melanin in fruit?
26 DENATURATIONAltering the shape of an enzyme in this manner is called DENATURATIONWhen an enzyme is denatured, it does not fit with the substrateActivation energy requirements return to their normal level, which is often too high for the reaction to proceed at normal temperaturesDenaturation is usually not reversible.
28 What Other Factors May Affect The Rate of Enzymatic Reaction
29 Concentration and Reaction Rate Because the relationship between substrate and enzyme is so specific, changing the number of enzymes reacting with the substrate (or vice versa) may affect the rate of reactionEx: Vmax
30 Temperature and Reaction Rate Temperature is a measurement of molecular speedAt a lower temperature, molecules collide less frequentlyAt higher temperatures molecules collide more frequentlyEnzymes tend to have an optimal temperature at which they function