Enzyme Lab Notebook Format
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1) Title/Date
2) Pre-lab (Key Concepts, Equations, Materials)
3) Purposes (2-3)
4) Personal Account
5) Discussion– only 1 question (on bottom of pg 3 of
packet)
• 6) Conclusion
Lab 2: Enzyme catalysis
Guaiacol + 2H2O2
(colorless)
peroxidase
Enzyme = peroxidase
Substrate = peroxide (H2O2)
How will we measure enzyme function?
- Color change using a spectrophotometer
tetraguaiacol + 8H2O
(brownish orange)
How does a spectrophotometer work?
Take home points
1.Light at a specific wavelength is sent through a liquid sample
2.Light passing through the sample is detected on the other side
3.To measure this accurately, we must calibrate (blank) the spec.
4.Calibrating the spec sets the range & “tells” the spec:
- what 0% light is (darkness)
- what 100% light is (all light passing through)
-For our experiment we will see how the amount of light passing through
changes as the reaction proceeds.
Tube #1
(blank)
Tube #2
Tube #3
Guaiacol
0.1 mL
(2 drops)
0.1 mL
(2 drops)
---
H2O2
---
0.2 mL
(4 drops)
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1.0 mL
(20 drops)
5.0 mL
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Turnip extract 1.0 mL
(peroxidase) (20 drops)
dH2O
1.
2.
3.
4.
5.
6.
7.
5.2 mL
Set wavelength to 500 nm
With the chamber empty, use left knob to adjust to 0% T
Insert tube #1 (blank) into spec & use right knob to adjust to 100% T
Pour #2 into #3 & begin timing immediately!!
Invert 2X quickly & place into spec
Record %T every 10 sec for 120 secs
From page 3, choose your experiment for tomorrow
• This weekend:
-Work on Enzyme Lab Entry
-Work on Pocket Mouse Signaling Packet
-BOTH due on TUESDAY!
• Enzyme Lab Overview
– Only hypothesis/procedure/data from FRIDAY needs to
be included.
– Slope calculation for EACH of your four lines
• ΔY / ΔX
(Units = Y units / X units)
– Discussion section (section #5) is only ONE question!
• Please put your LAB NOTEBOOK in the blue
crate.
• Please put your MOUSE SIGNALING PACKET in
the appropriate homework file.
– Make sure your name is on the packet!
• Unit 4 Test Review Session (Q&A)
– TOMORROW (Wednesday) at 7:00am
– TEST REMINDERS:
• 1) Don’t forget about your “Potential FRQ” sheet…you
got this on Tuesday, Nov. 24th
• 2) Don’t forget about your “Math Practice” sheet…you
got this in mid-November. Answers are posted online
under Ch. 7 PPT notes
• ENZYME LAB OVERVIEW:
• #1: Varied Concentration of Enzyme (peroxidase)
– More enzyme = faster reaction
• #2: Varied Concentration of Substrate (H2O2)
– Less substrate = slower reaction
– More substrate = faster reaction
– Even more substrate = slower reaction
• #3: Varied Environmental Temperature
– Body temp = fastest rate
• #4: Varied Environmental pH
– pH 8 = slow reaction; pH 5 = slow reaction
• #5: Varied Exposure Times to Boiling Water
– Reaction stops completely when enzyme boiled