Enzymes: “Helper” Protein molecules 2009-2010

Flow of energy through life Life is built on chemical reactions

Chemical reactions of life Processes of life ______________ molecules ______________ + +

Nothing works without enzymes! How important are enzymes? ____________________________________________________________________ building molecules ___________________ breaking down molecules __________________________________ “catalysts” enzyme + enzyme We can’t live without enzymes! +

Examples __________________ + enzyme __________________ + enzyme

Enzymes are proteins ________________________________________________________________________ each enzyme needs to be the ___________ for the job enzymes are named for the reaction they help ___________ breaks down ___________ ___________ breakdown ___________ ___________ builds ___________ Oh, I get it! They end in -ase

Enzymes aren’t used up ____________________________________ used only temporarily re-used again for the same reaction with other molecules very little enzyme needed to help in many reactions ____________ ____________ ____________ ____________

It’s shape that matters! _______________________ ________________ allows enzyme & substrate to fit ______________ ______________ ______________ ______________

1 2 3

Enzyme vocabulary _________________ _________________________ helper protein molecule molecule that enzymes work on _________________________ what the enzyme helps produce from the reaction part of enzyme that substrate molecule fits into

What affects enzyme action _______________________________ correct order of amino acids _______________________

Order of amino acids _______________________________________

Temperature Effect on rates of enzyme activity _________________________ greatest number of collisions between enzyme & substrate human enzymes = ___________________________________ _________________________________ molecules move slower decrease collisions

What’s happening here?! Temperature reaction rate temperature

How do cold-blooded creatures do it? Enzymes work within narrow temperature ranges. Ectotherms, like snakes, do not use their metabolism extensively to regulate body temperature. Their body temperature is significantly influenced by environmental temperature. Desert reptiles can experience body temperature fluctuations of ~40°C (that’s a ~100°F span!). What mechanism has evolved to allow their metabolic pathways to continue to function across that wide temperature span?

pH Effect on rates of enzyme activity ____________________________________ depends on where in body pepsin (stomach) = pH 3 trypsin (small intestines) = pH 8

pH stomach pepsin intestines trypsin reaction rate pH 1 2 3 4 5 6 7 8 What’s happening here?! pH stomach pepsin intestines trypsin reaction rate 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH

For enzymes… What matters? __________! 2009-2010