Regents Biology A. Flow of energy Life is built on chemical reactions
Regents Biology B. Chemical reactions of life Processes of life building macromolecules Dehydration synthesis breaking down macromolecules Hydrolysis ++
Regents Biology C. Enzymes How important are enzymes? all chemical reactions in living organisms require enzymes to work enzymes speed up reactions Act as catalysts ++ enzyme We can’t live without enzymes!
Regents Biology D. Activation Energy Is energy needed to get a reaction started Enzymes act by lowering the activation energy
Regents Biology E. Enzymes are proteins Each enzyme is the specific helper to a specific reaction needs to be the right shape are named for the reaction they help sucrase breaks down sucrose DNA polymerase builds DNA Oh, I get it! They end in -ase
Regents Biology F. Enzymes aren’t used up Enzymes are not changed by the reaction used only temporarily re-used again for the same reaction enzyme substrateproduct active site
Regents Biology G. It’s shape that matters! Lock & Key model shape of enzyme & substrate must ‘fit’ specific enzyme for each reaction
H. What affects enzyme action? Correct protein structure (amino acid chain) Temperature pH (acids & bases) why? enzyme has to be right shape
Regents Biology I. Temperature Effect on rates of enzyme activity Optimum temperature greatest number of collisions between enzyme & substrate human enzymes 35°- 40°C Raise temperature (boiling) denature protein = unfold = lose shape
Regents Biology 37° Temperature temperature reaction rate What’s happening here?! What is optimum temp for human enzymes?
Regents Biology J. pH Effect on rates of enzyme activity changes in pH changes protein shape most human enzymes = pH 6-8 pepsin (stomach) = pH 3 trypsin (small intestines) = pH 8
Regents Biology 7 pH reaction rate 20134568910 stomach pepsin intestines trypsin What’s happening here?! 11121314 Which environment does pepsin work best – acidic or basic?
Regents Biology How do cold-blooded creatures do it?
Regents Biology 2009-2010 For enzymes… What matters? SHAPE!
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 Order of amino acids Wrong order = wrong shape = can’t do its job! DNA chain of amino acids folded protein right shape! wrong shape!