Presentation on theme: "Enzymes!. Enzymes! Proteins Biological catalysts that speed up the rate of chemical reactions They help make products faster! Never used up! “Matchmaker”"— Presentation transcript:
3 ProteinsBiological catalysts that speed up the rate of chemical reactionsThey help make products faster!Never used up!“Matchmaker”ENZYMES!!!
4 Enzymes in ActionEnzymes speed up chemical reactions that take place in cellsThey DECREASE ACTIVATION ENRGYThe energy needed to get the reaction started (or energy needed to start making product)
5 break up hydrogen peroxide Catal-ASE is an enzymethat helpsbreak up hydrogen peroxide
6 Proteins: Enzymes What is a chemical reaction? Do they happen on their own?If we stare at the piece of paper, are we going to be able to make the oxygen molecules in the air collide with the cellulose in the paper?What do we need to do?What are reactants?What are products?
8 Examples of endothermic reactions: Melting of ice absorbs energyDissolving ammonium nitrate in water( the essence of commercial cold packs)Examples of exothermic reactions:Digestion of food releases energyAll combustion reactions (fires)C + O2 CO2 + EAdding an alkali metal to water2 Na + 2 H2O 2 NaOH + H2 + ECondensation of waterExplosion of bombs
9 Endothermic Reactions the reactants have less potential energy than do the products. Energy must be input in order to raise the particles up to the higher energy level.Energy + A + B --> AB
10 Exothermic Reactionsthe reactants have more potential energy than the products have. The extra energy is released to the surroundings.A + B --> AB + Energy
11 Enzymes Substrate Molecule/compound that attaches to enzyme CatalystAnything that speeds up the rate of a reaction by lowering the ACTIVATION ENERGYActiv. E: energy required for a chem. Rxn to start making productsused to regulate the rate (speed) of chemical reactionsProtein that helps speed up a reaction that occurs in a biological systemName of enzymes end in –ASEall enzymes are proteins, but not all proteins are enzymeseach chemical reaction in an organism requires its own specific enzymeenzymes are never changed by their reactions!SubstrateMolecule/compound that attaches to enzymeActive SiteSpecific location on enzyme for substrate to attachWhere the enzymatic reaction occursEnzyme-substrate complexWhen substrate binds to active site of enzymeProductsmolecules produced at the end of an enzymatic reaction
12 Factors that Effect the Rate of Reactions TemperatureHotBreaks bonds that give proteins its tertiary structure DENATURESColdSlow down chemical reaction (formation of enzyme substrate complex)pHAcids and bases produce OH- and H+ ionstoo many ions are present, the enzyme may be denatured (twisted and pulled so out of shape that it can no longer function)InhibitorsNon-competitivereact with portions of the active site, changing of its shapeAllosteric InhibitorsChange shape of the enzymeAttach to regulatory site (not active site) and change the shape of the entire enzyme (specifically the active site)Competitivelook like substrate, bind to active site, but do not make the intended product
14 Acetylcholinesterase catalyzes the breakdown of the neurotransmitter acetylcholine at several types of synapses as well as at the neuromuscular junction — the specialized synapse that triggers the contraction of skeletal muscle.One molecule of acetylcholinesterase breaks down 25,000 molecules of acetylcholine each secondmakes possible the rapid "resetting" of the synapse for transmission of another nerve impulse.
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