1 / 17

Enzymes: “Helper” Protein molecules

Enzymes: “Helper” Protein molecules . +. +. Chemical reactions of life. Processes of life building molecules synthesis breaking down molecules digestion. enzyme. +. enzyme. +. Nothing works without enzymes!. How important are enzymes?

chandra
Download Presentation

Enzymes: “Helper” Protein molecules

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Enzymes: “Helper” Protein molecules

  2. + + Chemical reactions of life • Processes of life • building molecules • synthesis • breaking down molecules • digestion

  3. enzyme + enzyme + 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” We can’t live without enzymes!

  4. Enzymes • 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.

  5. + enzyme enzyme + Examples • synthesis • digestion

  6. 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

  7. active site 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 substrate product enzyme

  8. It’s shape that matters! • Lock & Key model • shape of protein allows enzyme & substrate to fit • specific enzyme for each specific reaction

  9. 2 1 3

  10. 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

  11. What affects enzyme action • Correct protein structure • correct order of amino acids • why? enzyme has to be right shape • Temperature • why? enzyme has to be right shape • pH (acids & bases) • why? enzyme has to be right shape

  12. Order of amino acids • Wrong order = wrong shape = can’t do its job! foldedprotein chain ofamino acids DNA right shape! foldedprotein chain ofamino acids wrong shape! DNA

  13. Temperature • Effect on rates of enzyme activity • Optimum temperature • greatest number of collisions between enzyme & substrate • human enzymes • 35°- 40°C (body temp = 37°C) • Raise temperature (boiling) • denature protein = unfold = lose shape • Lower temperature T° • molecules move slower • fewer collisions between enzyme & substrate

  14. 37° Temperature humanenzymes What’s happening here?! reaction rate temperature

  15. pH • Effect on rates of enzyme activity • changes in pH changes protein shape~ Denatures • most human enzymes = pH 6-8 • depends on where in body • pepsin (stomach) = pH 3 • trypsin (small intestines) = pH 8

  16. pH stomachpepsin intestinestrypsin What’s happening here?! reaction rate 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH

  17. SHAPE! For enzymes…What matters?

More Related