ENZYME CATALYSIS 9172020 1 ENZYMES n n Globular

ENZYME CATALYSIS 9/17/2020 1

ENZYMES n n Globular Proteins Active Site One Substrate only Induced Fit: Changes occur when meet with substrate 9/17/2020 2

ENZYME CATALYSIS n 9/17/2020 Enzymes Catalysis - ↓ Activation Energy - Faster Reaction without change of form. n Factors affecting change: p. H, temperature 3

BEFORE THE LAB Find out rate - enzyme catalase substrate → product n Hydrogen peroxide = substrate n amount of hydrogen peroxide remain after reaction → titration with KMn. O 4 n Titration - add KMn. O 4 - color change until target color n 9/17/2020 4

LAB n 1. Add 10 ml of H₂O₂to each of 7 beakers. n 2. Add 1 ml of catalase to the first beaker at 0 second. n 3. Observe the reaction until the time labeled on the beaker. n 4. Stop the reaction by adding 10 ml of H 2 SO 4 n 5. Repeat the process for other remaining beakers. 9/17/2020 5

TITRATION 1. Remove a 5 ml sample for titration and move the sample to a clean flask. n 2. Record initial burette reading. n 3. Add n (purple) until faint brown color persists (it is the endpoint of process. ) n 4. Record final burette reading. n n KMn. O 4 5. Calculate the ml of KMn. O 4 used to reach the endpoint. 6. Repeat the process for other remaining beakers. 9/17/2020 6

* KMn. O 4 to the flask - mix - lose color - all peroxide reacted with KMn. O 4 → additional KMn. O 4 light brown or pinkish n n * KMn. O 4 ↑ - peroxide ↑ We calculate the rate of a reaction by measuring or observing the disappearance of substrate or the appearance of product. This lab figured out the rate at which the enzyme catalase converts substrate to product by observing the disappearance of substrate. 9/17/2020 7

Bibliography 1. Lab. Bench http: //www. phschool. com/science/biology_place/labbench/lab 2/active. html 2. Drug Strategies to Target HIV http: //www. chemistry. wustl. edu/~edudev/Lab. Tutorials/HIV/Drug. Str ategies. html 9/17/2020 8