2Chemical reactions of life Processes of lifebuilding moleculessynthesisbreaking down moleculesdigestion++
3Nothing works without enzymes! How important are enzymes?all chemical reactions in living organisms require enzymes to workbuilding moleculessynthesis enzymesbreaking down moleculesdigestive enzymesenzymes speed up reactions“catalysts”enzyme+enzymeWe can’t live without enzymes!+
4Enzymes A protein catalyst Enzymes are important proteins found in living things. An enzyme is a protein that changes the rate of a chemical reaction.They speed metabolic reactions.
6Enzymes are proteinsEach enzyme is the specific helper to a specific reactioneach enzyme needs to be the right shape for the jobenzymes are named for the reaction they helpsucrase breaks down sucroseproteases breakdown proteinslipases breakdown lipidsDNA polymerase builds DNAOh, I get it!They end in -ase
7Enzymes aren’t used up Enzymes are not changed by the reaction used only temporarilyre-used again for the same reaction with other moleculesvery little enzyme needed to help in many reactionssubstrateproductactive siteenzyme
8It’s shape that matters! Lock & Key modelshape of protein allows enzyme & substrate to fitspecific enzyme for each specific reaction
10Enzyme vocabulary Enzyme Substrate Products Active site helper protein moleculeSubstratemolecule that enzymes work onProductswhat the enzyme helps produce from the reactionActive sitepart of enzyme that substrate molecule fits into
11What affects enzyme action Correct protein structurecorrect order of amino acidswhy? enzyme has to be right shapeTemperaturepH (acids & bases)
12Order of amino acids Wrong order = wrong shape = can’t do its job! DNA folded proteinchain of amino acidsDNAright shape!folded proteinchain of amino acidsDNAwrong shape!
13Temperature Effect on rates of enzyme activity Optimum temperature greatest number of collisions between enzyme & substratehuman enzymes35°- 40°C (body temp = 37°C)Raise temperature (boiling)denature protein = unfold = lose shapeLower temperature T°molecules move slowerfewer collisions between enzyme & substrate
14Temperature 37° human enzymes reaction rate temperature What’s happening here?!37°reaction ratetemperature
15pH Effect on rates of enzyme activity changes in pH changes protein shape~ Denaturesmost human enzymes = pH 6-8depends on where in bodypepsin (stomach) = pH 3trypsin (small intestines) = pH 8