GROUP+3

By Gabby Fiorino, Rachel Mollozzi, Brielle Soluri, Julie Metrione, Matt Song
 * Title: Testing the effects pH levels have on enzyme reactivity**


 * Hypothesis- If the pH is lower, then the disk will rise quicker.**

Enzymes are substances that are produced by a living organism that acts as a catalyst to get a particular biochemical reaction. Enzymes are also called “organic catalysts,” since they are the major controls to most chemical activity in living systems. Enzymes are never changed during any kind of reaction, so they can be reused several times. Enzymes consist of one or more polypeptide chains, whose names will end in “-ase.” All enzymes contain protein nature and an active site. All enzymes have specific functions. They must form a substrate, or a relationship that is not permanent with the substance or substance whose reactions rate it affects. Also, this relationship between the enzyme and substrate is thought to require a close physical bond between the molecules, also known as enzyme-substrate complex. The enzyme action occurs, while the enzyme-substrate is formed. - Water - Tweezers - Beakers (6) - Peroxide - Sulfuric Acid - Base - Timer - pH strips - Safety Goggles - Tape
 * What are enzymes? What are their roles?**
 * Materials:**


 * Table 1: Trial 1**
 * Substance || Time ||
 * pH 1 || 23 seconds ||
 * pH 3 || 6 seconds ||
 * pH 5 || 5 seconds ||
 * pH 7 || 7 seconds ||
 * pH 9 || 10 seconds ||
 * Table 2: Trial 2**
 * Substance || Time ||
 * pH 1 || 10 seconds ||
 * pH 3 || 6 seconds ||
 * pH 5 || 7 seconds ||
 * pH 7 || 6 seonds ||
 * pH 9 || 11 seconds ||
 * Table 3: Trial 3**
 * Substance || Time ||
 * pH 1 || 12 seconds ||
 * pH 3 || 6 seconds ||
 * pH 5 || 13 seconds ||
 * pH 7 || 16 seconds ||
 * pH 9 || 76 seconds ||
 * Average Speed**
 * pH # || Average Time (seconds) ||
 * pH 1 || 15 ||
 * pH 3 || 6 ||
 * pH 5 || 8 ||
 * pH 7 || 10 ||
 * pH 9 || 9 ||

- **//Explaining the effect of your variable on your experiment.//** In this experiment the effects pH level had on the enzyme catalase. In the experiment it seemed pHs that were moderate (ex: pH 7, pH 5) showed the best results. When the pH was too low or too high, the reactivity took longer. This shows that enzymes works best when they are exposed to a pH 7, or a pH close to that. The rate at which a enzyme reacts can be predicted if the pH is known. When a pH is too high or low, the reaction of an enzyme is greater

//**- How do your experimental findings compare with accepted scientific knowledge of factors affecting enzyme activity? Explain.**// In science, it is generally accepted that pH levels do affect enzyme activity. The rate at which the paper rises is different for different enzymes. For hydrogen peroxide, the optimum pH is 7. Our experimintation actually shows that the farther the ph was from 3, the slower it took to come back to the surface. Our evidence said that pH 3 would be the fastest.

**//- What improvements would you make your experimental design if you had more time and materials?//** **//In this lab, the pH was tested of five different substances. By testing the levels of the pH, if the pH were lower, then the disk on the top would rise more quickly. Since there was limited time to test this lab, more time would have allowed more tests for the pH levels to be run. Then, there would have been more pH levels of several different substances to compare, hopefully getting the most accurate conclusion. Also, if more than one group would complete this lab, there would have been more data to compare, to see how several conclusions differed. By comparing, we could see the differences between our substances over time. Thirdly, if the substances were leftout for a day and recorded the changes of the pH level, the pH would havechanged in shape and/or temperature. Then, the experiment would be taking the pH of each substance, placing a disk in each beaker, and finally conclude if the disk rose more quickly with a lower or higher pH. //**

//**Set Up:**//