P51™ Enzyme Lab: β-Gal Glow™

Intermediate—Easy to perform; requires some background knowledge.
This lab enables students to investigate enzyme activity and the conditions that affect it. Under optimal conditions enzymes catalyze, or speed the rate of, chemical reactions. In this lab, a substrate that is not fluorescent under basal conditions will fluoresce under blue light when sugar molecules are removed through hydrolysis by the enzyme beta-galactosidase. Observing how brightly the solution fluoresces over time allows students to observe the reaction progress, and to quantify the effect of different factors on enzyme efficiency.

The lab is structured as 4 inquiry-based investigations. In each investigation, students explore the effect of the following factors on enzyme reaction rate:

• pH
• Temperature
• Enzyme and substrate concentration
• Competitive inhibition

Enough reagents are provided for 8 lab groups (32 students) to each pursue at least 2 of the investigations. This activity is compatible with blueGel™ (item #213900), P51™ Molecular Fluorescence Viewer (item #216321), or other blue light transilluminator systems (not included) and gives students practice with micropipets and using fluorescence to detect enzyme activity. It can be completed in one 45-minute class period or be extended to two 45-minute periods. Note: Reagents require refrigerated storage and have a shelf life of 6 months when stored at 4° C.