LAB4Takehome_Cellbio

Dataset: Use the dataset provided on the last page. The data supplied is what was expected to occur in your lab, but if you did something wrong or if the enzyme for some reason didn’t work, you may not have appropriate data to work with. INSTRUCTIONS: Use the standard curve formula to convert each absorbance value into an amount of starch (  g). Create a single graph with two lines, one line for the control (the reaction without inhibitor added), and the second line for the inhibitor (the reaction with inhibitor added). The curved trendline options don’t work very well, so I recommend connecting the markers with smooth lines. In Excel, the graph type is called a “ scatterplot with smooth lines and markers ”. Avoid the “2D line” charts. Paste or import your graph into this document then move to the next page BIOL2321 | 2022 4- 1

QUESTIONS: 1. Use the graph to decide whether or not the inhibitor slows the reaction rate. Breifly explain why or why not. The inhibitor did in fact slow down the reaction rate of the breakdown of starch. The control data shows the steady decreasing of starch over time, but the inhibitor data shows a slower rate of reaction. At the end of the reaction (at 30 minutes), the control data has a lower concentration of starch (3.87 µg) than that of the inhibitor, which has a higher concentration of starch (20.13 µg). This tells me that the inhibitor had a slower rate of reaction (took more time to breakdown the starch). 2. Look up the definitions of both a competitive inhibitor and non-competitive inhibitor . Read over the definitions, then use the definitions to explain what would happen to the diagram below given the situation in the description. The rectangle in blue is the enzyme itself. The active site is the upside-down triangle at the top, and the allosteric site is the circular space at the bottom. A) A competitive inhibitor is present in a cell along with the substrate for the enzyme. What SHAPE is the substrate? What SHAPE is the inhibitor? What happens when the inhibitor binds to the enzyme? The shape of the substrate would be an upside-down triangle (a similar shape to the active site). The shape of the inhibitor would also be an upside-down triangle (similar shape to the substrate so that it can fit into the active site). When the inhibitor binds to the enzyme, it blocks the substrate from binding and the reaction can no longer happen, or the reaction would slow down. B) A non-competitive inhibitor is present in a cell along with the substrate for the enzyme. What SHAPE is the substrate? What SHAPE is the inhibitor? What happens when the inhibitor binds to the enzyme? BIOL2321 | 2022 4- 2

Lab 4 Take-home assignment Time (in minutes) Absorbance (A 580nm ) Calculations of the amount of starch remaining (µg) Amount of starch remaining (µg) 0 1.793 1.793/0.015 119.53 5 1.026 1.026/0.015 68.40 10 0.476 0.476/0.015 31.73 15 0.263 0.263/0.015 17.53 20 0.160 0.160/0.015 10.67 25 0.091 0.091/0.015 6.07 30 0.055 0.055/0.015 3.67 Inhibitor Data Time (in minutes) Absorbance (A 580nm ) Calculations of the amount of starch remaining (µg) Amount of starch remaining (µg) 0 1.931 1.931/0.015 128.73 5 1.555 1.555/0.015 103.67 10 0.953 0.953/0.015 63.58 15 0.641 0.641/0.015 42.73 20 0.457 0.457/0.015 30.47 25 0.372 0.372/0.015 24.80 30 0.302 0.302/0.015 20.13 Once you’re finished, please upload this file to the Lab 4 take-home assignment Dropbox on Brightspace. This assignment is due by 7 days after your lab assignment was due (in other words, by 5:30pm on either Saturday March 18 th or Saturday March 25 th ). 5- 4 2021 | BIOL2321

Enzyme Inhibitor Lab 5 This is glucose: Starch is made of many glucose molecules linked together in a chain: The natural substrate of alpha-amylase is starch. Alpha-amylase cuts the bond between adjacent glucose molecules to make shorter starch molecules or to release glucose. We are testing a potential inhibitor of alpha-amylase named acarbose (a similar structure to starch 78) Dataset: CONTROL: Time (min) A 580 Amount of starch remaining (  g) Blank - BIOL2321 | 2021 5- 5