Presentation on theme: "Warm Up Base your answer to this question on the diagram below, which represents stages in the digestion of a starch, and on your knowledge of biology."— Presentation transcript:
1 Warm UpBase your answer to this question on the diagram below, which represents stages in the digestion of a starch, and on your knowledge of biology.The products would most likely containA. simple sugars. C. amino acids.B. fats. D. minerals.
3 Chemical ReactionsA. When bonds are broken and reformed to make different substances.EX:Reactants ProductsC6H12O6 + 6O2 6CO2 + 6H2ORemember, energy is stored in the bonds of the compounds.Reactants are also called raw materials – They need to know this term.Have them tell you the reactants and products of the above equation.
4 Chemical reactions of life Processes of lifeA. building molecules = synthesisB. breaking down molecules = digestion++
5 What is needed to start a reaction? Energy absorbedActivation energyReactantProductsEnergy releasedActivation Energy: energy required to get a reaction startedPoint out the high amount of energy needed with reaction in graph.The activation energy on the graph comes in when you click the mouse – the purpose is to get the answer from them first. – Remember enzyme demo
6 Nothing works without enzymes! How important are enzymes?A. all chemical reactions in living organisms require enzymes to workbuilding molecules = synthesis enzymesbreaking down molecules = digestive enzymes+enzymeWe can’t live without enzymes!+enzyme
11 Enzymes are proteins & each enzyme is the specific helper to a specific reaction. A. Each enzyme needs to be the right shape for the jobB. Enzymes are named for the reaction they helpi. sucrase breaks down sucroseii. proteases breakdown proteinsiii. lipases breakdown lipidsiv. DNA polymerase builds DNAOh, I get it!They end in -ase
12 Enzymes aren’t used up **Enzymes are NOT changed by the reaction A. used only temporarilyB. re-used again for the same reaction with other moleculesC. very little enzyme needed to help in many reactionssubstrateproductactive siteenzyme
13 It’s shape that matters! Lock & Key TheoryA. shape of protein allows enzyme & substrate to fitB. specific enzyme for each specific reactionSubstrateEnzymeProducts
14 What Affects Enzyme Activity Temperature:pH:Temperature: all enzymes have an optimal temp they work best atpH: acidity/alkalinity can increase or decrease the function of an enzymeConcentration: Increasing the concentration of the enzyme can increase the rate of the chemical reaction37591113NeutralBattery AcidBleachBlood (7.5)
15 Temperature & Effect on Rates of Enzyme Activity A. Optimum (best) temperaturei. greatest number of collisions between enzyme & substrateii. human enzymes = 35°- 40°C (body temp = 37°C)B. Raise temperature (boiling)i. denature protein = unfold = lose shapeC. Lower temperaturei. molecules move slowerii. fewer collisions between enzyme & substrate
16 Temperature human enzymes Reaction Rate Temperature ( ̊ C) 37° What’s happening here?!37°Reaction RateTemperature ( ̊ C)
17 pH & Effect on Rates of Enzyme Activity A. changes in pH = changes protein shapeB. most human enzymes work best at pH 6-8i. depends on where in bodyii. pepsin (stomach) = pH 3iii. trypsin (small intestines) = pH 8
19 DenatureA. When enzymes are exposed to extreme pH or high temperatures, they can denatureB. When denatured, an enzyme will no longer function, due to a change in enzyme structureC. This is why running high fevers for extended time is cause for concern
20 Enzyme vocabulary review Protein; speeds up chemical reactions by lowering activation energySubstratemolecule that enzymes work onProductswhat the enzyme helps produce from the reactionActive sitepart of enzyme that substrate molecule fits into