380 likes | 613 Vues
Enzyme – Biological Catalyst (Part ii). Objectives for today. Mode of actions of enzymes Naming of enzymes Specificity of enzymes. Overview . Biological Molecules. Water and Living Organisms . Carbohydrates, Fats and Proteins . Enzymes . Lock & Key hypothesis. Specificity.
E N D
Objectives for today • Mode of actions of enzymes • Naming of enzymes • Specificity of enzymes
Overview Biological Molecules Water and Living Organisms Carbohydrates, Fats and Proteins Enzymes Lock & Key hypothesis Specificity Factors affecting enzyme reactions Speed up chemical Rxn Mode of Action Not chemically altered at the end Of Rxn pH Temperature Lowering Activation Energy
Recap • Enzymes are biological catalysts found in both plants and animals. • Catalysts are….?
Cut the wire Speed up the cutting process! Scissors After cutting, still remain as a scissors! Not altered!
Enzyme as biological catalyst Speed up the chemical reaction! Like condensation and hydrolysis ENZYME Not chemically altered at the end of the reaction!
3. Lower Activation energy Exam! Normal Day 7:29am Products = “ You in school with uniform” 6:20am Reactants = “ You in bed in home clothes”
3. Lower Activation energy With Enzymes! Without Enzymes Products = “Glucose molecules” Reactants = “ Starch + Water”
Demonstration on the breakdown of starch by enzyme (amylase) Saliva contain amylase, an enzyme that breaks complex carbohydrates (starches) into simple sugar (glucose)
“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!”
Mode of action • Enzymes reaction depends on the availability of active sites • Active sites are depression or “pockets” on the surface of an enzyme molecule into which substrate molecule can fit. • The substrates binds to the enzyme, forming an enzyme-substrate complex • Reactions takes place at the active sites to convert the substrate molecules into product molecules • The products separates, leaving the enzyme unaltered and free to combine again with more substrate molecules.
Activity time! Make your own enzyme! • Using plasticine to model enzymes mode of actions! • Split into 4 groups • Each group take a set of plasticine
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.
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.
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
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?
I. Name that Enzyme !!! Protein ase Substrate Name + -ase
EnzymeS Name That Enzyme
I. Name that Enzyme !!! Lipid ase
I. Name that Enzyme !!! Carbohydrate ase
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.
HW- Due Next Tue 31st 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?
Review questions • 1) Are Enzymes: A - Carbohydrates B - Protiens C - Nucleic Acids D - Lipids E - Other
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
Next lesson • Factors affecting enzymatic reactions