Download Enzyme Investigation

Enzyme Investigation
Demonstrations:
I will demonstrate several enzymes in action. Fill in the chart below:
Demonstration
Enzyme
Substrate
What happened
Potato and Hydrogen
peroxide
Yeast and discs
Gelatin and laundry
detergent
Milk and Lactaid
Starch plate and
saliva
Instructions
1. Get 80 Toothpicks and put into 3 piles of 20.
2. Person A: Have one person watch the clock for 20 seconds
Person B: will break as many toothpicks as he/she can for that 20 seconds Without looking at the pile.
Person C: Will count how many toothpicks are broken in that 20 seconds and record the number.
3. Repeat step 2 and average the total number of toothpicks broken in 20 seconds.
# Broken in Trial 1: ___
# Broken in Trial 2: ___
Average Rate: __
4. Using ice water or gloves repeat the process for the last pile.
Questions
1. What was your average # of toothpicks that toothpickase can break in 20 seconds?
2. What happens to how fast the enzyme can work if you put gloves on or chilled your hand? Why? How
does this relate to real enzymes?
3. What do your hands represent? _________________________
4. What do the whole toothpicks represent? _______________________
5. What do the broken toothpicks represent? _______________________
6. How is your hand similar to an active site?
7. Why did we put the ase on the end of toothpick?
8. What if you were given a marshmallow to do the same thing with. Would toothpickase work for that
substrate as well? Why or why not?
9. If we were to use more than 20 toothpikcs in a pile, what do you think would happen to the rate? Why?
How does Enzyme Activity Change?
In this lab you are investigating a specific fact about enzyme action. With your group answer the following questions:
1. What would happen if your digestive system stopped producing enzymes?
2. Why do you think that?
3. What do you think might affect the rate at which enzymes catalyze reactions in your body? Why?
4. What happens to an enzyme after the reaction is complete? Why do you think that?
5. Will adding more enzyme increase the rate of a reaction? Why do you think that?
6. Do all enzymes work on the same substrates?
7. How do you know a reaction is occurring?
8. When does a reaction stop?
9. What methods might be used to measure reaction rates?
With your group you are going to test one of the enzyme rules. Choose 1 question below. Each question
can only be chosen by 1 group. You will design an investigation to find the answer to your question.
a. Do both plants and animals have an enzyme that breaks down hydrogen peroxide?
b. How does temperature affect enzyme activity?
c. How does pH affect enzyme activity?
d Can enzymes be reused?
e. Does the amount of enzyme used affect the enzyme rate?
f. Does the amount of substrate used affect enzyme rate?
Lab Design:
1. What question are you going to answer? _____________________________________________________
2. a. What will you use for your enzyme source? ___________________________
b. What will you use for your substrate source? ___________________________
3. What will your independent variable groups be?
4. What will you use for your control?
5. What would you keep constant throughout the experiment?
6. How will you measure the enzyme activity? (What will your dependent variables be?)
7. What will you record? (How will you set up your tables and graphs?)
8. Write up a procedure that you will follow step by step in the lab. (Be sure to include specifics about amount and time)
Get Ms. Lawrence’s Approval before your start!
Your Lab Report
Introduction
The introduction section is the place you explain to the reader any background information that he/she needs to
know in order to understand your lab. In this lab the following questions will be helpful to answer
a. What question are you trying to answer?
b. Describe the general structure and function of an enzyme?
c. Describe what happens in an enzyme catalyzed reaction. Include diagrams in your explanation.
d. What is your hypothesis for the experiment?
e. What was the enzyme, substrate, and product in your reaction?
f. What is your independent variable, dependent variable, and control?
Materials and Methods
This section is the place you LIST your materials and then provide a step by step procedure. Remember, only experiments
that are repeatable are accepted in the scientific community, therefore, make sure another person could follow your steps.
Results and Tables and Graphs
In this section provide your written results of what happened. Any data tables you used can go into this section as well.
Make sure you include captions that explain the diagrams, tables, and graphs you choose to use.
Conclusion/Reflection questions
Your conclusion section is the place you comment and analyze your data. It should contain the following:
a. A reflection on your hypothesis (were you right or wrong?)
b. What errors that you could change in the future occurred?
c. What errors were out of your control occurred?
d. How can your investigation on enzyme activity be applied to real world situations?
e. How can we manipulate enzymes in the environmental industry to benefit an ecosystem?
Lab Report Rubric
Title
___0-10 Introduction
* Purpose of lab (What question were you investigating?)
* Any background information that is relevant to the reader to understand the lab.
* Independent Variable and Dependent Variable Present
* Hypothesis (includes why, and matches your independent variable)
_____/0-10 Materials and Methods
* List of Materials Present and materials are not left out (Be specific and describe what you used. For example,
say 100 mL beaker rather than only listing beaker)
* Methods are step by step and are logical in order and could be followed by another person (be very
specific on what you did. Include measurements and amounts you used and the lengths of time you followed)
* Control group is included
* Methods are only testing one independent variable
* Constants
____/0-10 Results/Tables and graphs
* Figures are neat
* Figures have captions under them explaining what the graphic means.
* All have titles and axes’ are labeled
* Organized and reported concisely.
* Does not include Conclusions (Do not use the word Because in this section or the word Why)
___/0-15 Discussion, Conclusions, and Error
* Explains the effect the results have on the scientific question.
* Relates directly to the introduction – mention your hypothesis and how the answer you found for it.
* Errors explained
*Reflection Questions are answered. (You can also answer questions that you asked as well)
____/0-5 Technical Execution: (Read these Carefully!!!)
* Paper is typed; double spaced, and all sections are labeled with the appropriate heading
* Smoothly constructed, concise sentences and paragraphs
* Proper grammar and spelling is used
Total Points: _____________/50
A: 45-50 Points. All sections have required information. The format is correct. Student shows mastery of lab
concepts and processes. Safety measures were taken and followed. Student was able to make appropriate
conclusions and reflect on the lab.
B: 40-44 Points: Sections have most of the required information. The paper has most of the technical elements.
The student shows a good grasp of lab concepts and processes but shows need of some improvement.
C: 35-39 points: Sections are missing required information. Format expectations were not met. Student shows
a need for improvement in scientific lab concepts and processes. Student’s conclusion was loosely supported
by the evidence. The lab would be difficult to replicate.
D: 30-34 points: Sections are missing many required parts. Student’s conclusion was not supported by
evidence. The methods are written vaguely and could not be followed by another person. Student shows little
knowledge of scientific concepts and processes.
F: 29 and below: Student did not meet the expectations of most if not all sections of the lab. Student shows
little knowledge of scientific concepts and processes.