Name Chloe Ezell Group 2 Gene Expression Lab Lab Activity 1 Table 1 Culture Conditions Rxn Lysis Reagent LB only plain media 1a 1b 1c LB lactose 2a lactose culture 2b 2c LB glucose 3a glucose culture 3b 3c LB glucose 4a 4b lactose glucose lactose 4c culture BLANK Bla nk E coli Culture Volume 20 L 20 L 20 L 20 L 20 L 20 L 20 L 20 L 20 L 20 L 20 L 20 L 20 L 40 L 200 L 20 L 40 L 200 L 20 L 40 L 200 L 20 L 40 L 200 L 20 L 0 L Vol ONPG 4 mg mL for 0 8 mg Unused media for differences in enzyme 180 L 160 L 0 180 L 160 L 0 180 L 160 L 0 180 L 160 L 0 Z buffer to bring to 2 mL total 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 1380 uL 200 L 1380 uL 400 uL A420nm Activity A420nm time 1000 0 0077 0 0259 0 1321 0 0045 0 1107 0 6061 0 0040 0 0357 0 1584 0 0040 0 0588 0 1818 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL 400 uL Lab Activity 1 Table 2 Rxn 1a 1b 1c 2a 2b 2c 3a 3b 3c 4a 4b 4c Time started 0 00 0 15 0 25 0 50 1 00 1 10 1 40 1 50 2 00 2 30 2 40 2 50 Time stopped 43 15 38 45 26 55 34 20 26 35 17 40 43 30 39 10 7 15 43 45 39 30 27 35 Elapsed time sec 2595 2315 2590 2010 1535 990 2510 2220 1515 2475 2210 1485 0 02 0 06 0 21 0 009 0 17 0 60 0 01 0 08 0 24 0 01 0 13 0 27 1 Name Chloe Ezell Group 2 Lab Activity 2 Table 3 1 Tube 2 Culture Conditions Rxn L 20 Glucose L 20 Lactose E coli culture LB culture Lactose 1 50 L 0 L 950 L Glucose culture Lactose 2 50 L 0 L 950 L LB culture Glucose 3 0 L 50 L 950 L Lactose culture Glucose 4 0 L 50 L 950 L BLANK Table 3 2 Tube 1 Culture Conditions Rxn LB broth for differences in enzyme Lysis Reagent E coli volume from Tube 2 Vol ONPG Z buffer to bring to 2 mL 4 mg mL for 0 8 mg total LB culture Lactose 1 80 L 10 L 20 L 1690 200 Glucose culture Lactose 2 80 L 10 L 20 L 1690 200 LB culture Glucose 3 80 L 10 L 20 L 1690 200 Lactose culture Glucose 4 80 L 10 L 20 L 1690 200 BLANK 2 Name Chloe Ezell Group 2 Table 4 Rxn 1 2 3 4 Time started 0 10 0 10 0 10 0 10 Time stopped 1 44 59 29 20 00 52 10 00 26 10 00 Elapsed time sec 94 059 1750 3120 1560 A420nm 0 03 0 00 0 01 0 09 Activity A420nm time 1000 0 3189 0 0000 0 0032 0 0577 Create a graph of your results for Lab Activity 1 Plot enzyme activity vs enzyme concentration a b c for each treatment The graph should include a title labeled axes and labeled data lines 1 Under what conditions is the LacZ gene expressed Is there any sign of activation or repression Be sure to refer to your results when discussing your answer The LacZ gene is expressed when lactose is present and lac operon is started Repression occurs as the volume decreases while activation happens when the volume increases Allolactose binds to the protein which activates it 2 Examine your data for Lab Activity 2 Describe the data and your interpretation of what you see Based on the data from Lab Activity 2 sugar does have an interaction with the assay The allolactose found in E Coli binds to the protein instead of the ONPG which decreases the activity rate The lac operon deactivates in the presence of glucose which causes the repression This can be seen in table 4 3 Name Chloe Ezell Group 2 which shows the initial activation then repression due to the sugars then slight increase in activity once the sugar has been depleted 4
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