Regents Biology Enzymes: “Helper” Protein molecules
Regents Biology Flow of energy through life Life is built on chemical reactions
Regents Biology Chemical reactions of life Processes of life building molecules synthesis breaking down molecules digestion ++
Regents Biology Nothing works without enzymes! How important are enzymes? all chemical reactions in living organisms require enzymes to work building molecules synthesis enzymes breaking down molecules digestive enzymes enzymes speed up reactions “catalysts” ++ enzyme We can’t live without enzymes!
Regents Biology Enzymes are proteins Each enzyme is the specific helper to a specific reaction each enzyme needs to be the right shape for the job enzymes are named for the reaction they help sucrase breaks down sucrose proteases breakdown proteins lipases breakdown lipids DNA polymerase builds DNA Oh, I get it! They end in -ase
Regents Biology Enzyme vocabulary Enzyme helper protein molecule Substrate molecule that enzymes work on Products what the enzyme helps produce from the reaction Active site part of enzyme that substrate molecule fits into
Regents Biology Enzymes aren’t used up Enzymes are not changed by the reaction used only temporarily re-used again for the same reaction with other molecules very little enzyme needed to help in many reactions enzyme substrateproduct active site
Regents Biology It’s shape that matters! Lock & Key model shape of protein allows enzyme & substrate to fit specific enzyme for each specific reaction
Regents Biology Factors affecting enzyme function substrate concentration reaction rate Substrate concentration as substrate = reaction rate more substrate = more frequently collide with enzyme reaction rate levels off all enzymes have active site engaged enzyme is saturated maximum rate of reaction
Regents Biology 37° Temperature temperature reaction rate What’s happening here?!
Regents Biology Factors affecting enzyme function Temperature Optimum T° greatest number of molecular collisions human enzymes = 35°- 40°C body temp = 37°C Heat: increase beyond optimum T° increased energy level of molecules disrupts bonds in enzyme & between enzyme & substrate H, ionic = weak bonds denaturation = lose 3D shape (3° structure) Cold: decrease T° molecules move slower decrease collisions between enzyme & substrate
Regents Biology Enzymes and temperature Different enzymes function in different organisms in different environments 37°C temperature reaction rate 70°C human enzyme hot spring bacteria enzyme (158°F)
Regents Biology Factors affecting enzyme function Salt concentration changes in salinity adds or removes cations (+) & anions (–) disrupts bonds, disrupts 3D shape disrupts attractions between charged amino acids affect 2° & 3° structure denatures protein enzymes intolerant of extreme salinity Dead Sea is called dead for a reason!
Regents Biology 2009-2010 For enzymes… What matters? SHAPE!
Regents Biology Title: LAB 2: Factors Affecting Enzyme Activity Introduction: (What is the purpose of this lab?) Lab Report 4 sections Title: (ex: Enzyme Concentration) Introduction: Purpose of this specific experiment/what is your hypothesis? Results and Data: (Data table and graph) Conclusion (Explain your results, was your hypothesis supported, sources of error/improvement) Questions (1-4)