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ENZYME – BIOLOGICAL CATALYST (PART II)
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Objectives for today Mode of actions of enzymes Naming of enzymes Specificity of enzymes
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Overview Biological Molecules Water and Living Organisms Carbohydrates, Fats and Proteins Enzymes Lock & Key hypothesis Mode of Action Factors affecting enzyme reactions Speed up chemical Rxn Not chemically altered at the end Of Rxn Lowering Activation Energy Specificity Temperature pH
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Recap Enzymes are biological catalysts found in both plants and animals. Catalysts are….?
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Cut the wire Scissors Speed up the cutting process! After cutting, still remain as a scissors! Not altered!
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Enzyme as biological catalyst ENZYME Speed up the chemical reaction! Like condensation and hydrolysis Not chemically altered at the end of the reaction!
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3. Lower Activation energy Reactants = “ You in bed in home clothes” 6:20am Products = “ You in school with uniform” 7:29am Normal Day Exam!
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3. Lower Activation energy Reactants = “ Starch + Water” Products = “Glucose molecules” Without Enzymes With Enzymes!
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Demonstration on the breakdown of starch by enzyme (amylase) Saliva contain amylase, an enzyme that breaks complex carbohydrates (starches) into simple sugar (glucose)
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“Now that we know enzymes are catalysts, and roughly know its shape, but we still do not know how the enzymes interact with the reactants!”
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How does an enzyme really works?
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Mode of actions in 3D view!
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Mode of action 1. Enzymes reaction depends on the availability of active sites 2. Active sites are depression or “pockets” on the surface of an enzyme molecule into which substrate molecule can fit. 3. The substrates binds to the enzyme, forming an enzyme-substrate complex 4. Reactions takes place at the active sites to convert the substrate molecules into product molecules 5. The products separates, leaving the enzyme unaltered and free to combine again with more substrate molecules.
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2D view of enzyme in action 5
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Activity time! Using plasticine to model enzymes mode of actions! Split into 4 groups Each group take a set of plasticine Make your own enzyme!
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Objectives Make your own enzymes that fits the substrates given to you Time limit is 5mins After making, each group is supposed to describe the mode of actions of enzymes.
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Enzymes are specific
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Specificity of enzymes explained by the Lock and Key hypothesis One key only fits one lock! Inside the lock, it has a specific shape that only takes in the correct key with the correct complimentary shape.
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Enzymes are specific ◦ Each chemical reaction is catalysed by a unique enzyme ◦ A substrates fits into an enzyme’s activity site in a way similar to how a key fits into a lock. ◦ Lock and Key hypothesis
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How do we name our enzymes?
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How do Canberra name their classes? 3E1 All the sec 3 classes start with the number 3 Follow by E, N or T This allows people to quickly recognize the classes. So, how can we name enzymes so that people can recognize that the names given actually belongs to the enzymes and not something else?
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Name that Enzyme !!!
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I. Name that Enzyme !!! Protein ase Substrate Name + -ase
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EnzymeSEnzymeS Name That Enzyme
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I. Name that Enzyme !!! Lipid ase
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Carbohydrate ase I. Name that Enzyme !!!
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Enzyme Nomenclature and Classification: Enzymes are commonly named by adding a suffix "-ase" to the root name of the substrate molecule it is acting upon. For example, Lipase catalyzes the hydrolysis of a lipid triglyceride into fatty acids and glycerol. Sucrase catalyzes the hydrolysis of sucrose into glucose and fructose. A few enzymes discovered before this naming system was devised are known by common names. Examples are pepsin, trypsin, and chymotrypsin which catalyzes the hydrolysis of proteins.
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Quick facts
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Any Questions?
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Summary EnzymesCharacteristicsSpecific Speed up Chemical Rxn Lower activation energy Remains unaltered Requires in minute amount Mode of action Lock and key hypothesis Induced fit hypothesis
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Video on enzymes
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HW- Due Next Tue 31 st March Go to the biology blog canberra3E1.wordpress.com and do a short online quiz. Participation marks will be given. Watch a video posted on the web and State some common uses of enzymes in our society Scientist can create ‘super enzymes’ that can break down bio molecules very fast and efficient. Do you think it is safe to mass produce this and use it in our society?
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Review questions 1) Are Enzymes: A - Carbohydrates B - Protiens C - Nucleic Acids D - Lipids E - Other
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Going a bit further G6PD, a functional enzyme gone missing in in the body! Cannot break down Glucoe-6-Phosphate, which will be accumulated in the cells. And it disrupts many other chemical reaction in the body
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G6PD enzyme
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Next lesson Factors affecting enzymatic reactions
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