1 / 12

LAB 2 Enzyme Catalysis

LAB 2 Enzyme Catalysis. H 2 O 2 HYDROGEN PEROXIDE. 2 H 2 O 2 → 2 H 2 O + O 2. In aerobic organisms Toxic byproduct of metabolism Strong oxidizer (grabs electrons from other molecules). Substrate Products.

anaya
Download Presentation

LAB 2 Enzyme Catalysis

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. LAB 2Enzyme Catalysis

  2. H2O2 HYDROGEN PEROXIDE 2 H2O2 → 2 H2O + O2 • In aerobic organisms • Toxic byproduct of metabolism • Strong oxidizer • (grabs electrons from other molecules) Substrate Products Reaction happens spontaneously (slowly)

  3. Catalase ENZYME Speeds up reaction to break down hydrogen peroxide Tetramer (4 polypeptide subunits) Contains Porphyrin groups with iron cofactors = HEME ANTI-OXIDANT http://en.wikipedia.org/wiki/File:Catalase_Structure.png http://semicrystalline.wordpress.com/2007/05/

  4. Other molecules with porphyrin rings Hemoglobin Chlorophyll http://drvsrs.com/spimgs/HEMOGLOBIN.jpg http://www.fkp.jku.at/fkp/forschung/PorSil.aspx

  5. 2A Watch for bubbles • Repeat with boiled enzyme • Repeat with diced potato http://www.nealbrownstudio.com/adm/photo/163_nb_fried_egg.jpg

  6. 2B DETERMINE BASELINE AMOUNT of H2O2 +10 mL H2O2 +1 mL H2O +10 mL H2SO4 REMOVE A 5 mL SAMPLE Assay for Hydrogen Peroxide http://www.nealbrownstudio.com/adm/photo/163_nb_fried_egg.jpg

  7. ASSAY for presence of H2O2 5 H2O2 + 2 KMnO4 + 3 H2SO4 → K2SO4 + 2 MnSO4 + 8 H2O + 5 O2 Potassium permanganate (KMnO4 ) = Purple Add KMnO4 until solution stays a faint pink or brown Syringe Numbers runbackwards BURET

  8. 2D Enzyme Catalyzed Rate of H2O2 Decomposition 360 sec 180 sec 60 sec 90 sec 120 sec 30 sec RedoBaseline 10 sec + 10 mL H2O2 to each beaker For each time point+ 1 mL Catalase (yeast) Swirl gentlyAt appropriate time: add sulfuric acid( H2SO4 ) Assay for H2O2

  9. µmolesH2O2 used TIME (seconds)

More Related