Middle School Science and Engineering:
Glucose Analysis

Deanne Crichton
McIlvaigh Middle School
Tacoma, WA
Summer 1994

Introduction

Science

Science is the process of gathering and examining data then drawing conclusions. The final end product is to answer the question "Why?". Scientists are interested in investigating what happens and why. In many cases, they are less concerned about the practical applications of their investigations.

Engineering

According to the Engineers' Council for Professional Development, engineering is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to utilize economically the materials and forces of nature for the benefit of humankind. A more useful definition is that engineering is concerned with the use of scientific discoveries and formulating acceptable theories. Primarily engineering is conducted in teams where individuals use their expertise to help find the solution to a problem. Due to sophisticated technology, specialists must cooperate in the designing of processes and machinery.

Engineers work toward finding the answers to practical problems. They seek to provide newer, cheaper, and better means of using energy and materials to improve the quality of living/life. Initially, engineering was concerned with economics and scientific discoveries. Now engineers must increasingly take into account the effects on the environment and society.

Module Rationale

One of the goals of the Washington State University and National Science Foundation Institute for Science And Mathematics Education through Engineering Experiences, is to have participants prepare a teaching module that is appropriate for their classroom. This module will help to illustrate the connection between science and engineering. Students will be shown engineering principles that are applied in a diagnostic laboratory. This module is a result of work done in chemical engineering at Washington State University under the direction of Dr. Bernard Van Wie. The focus of the work is on developing inexpensive bioanalytical instruments for:

  1. rapid, automated, and simultaneous blood chemistry analyses for processing eight of the most common clinical tests.
  2. critical care diagnostics for near patient testing.
  3. general purpose flow injection analysis useful in industrial bioprocessing and biochemical laboratories.

Flow injection analysis (FIA) is the injection of a sample and reagent into a narrow tube. A pump forces the analyte, the fluid to be analyzed, through a chemical modulator into a detector. A chemical reaction occurs between the sample molecules and the reagent molecules. At the same time, there is dispersion of the sample zone within the area of the reagent. Some of the benefits of FIA are that it utilizes very small volumes of sample and reagent and it has a high sampling frequency.

Goals

General Goals

The goal of this module is to provide students with experience in using bioanalytical equipment. The students will be hypothesizing, observing, gathering data, graphing, analyzing, and inferring during inquiry based investigations.

Student Learning Objectives

By the end of this module, the student will be able to:

  1. gather data using a spectrophotometer.
  2. graph data into a calibration curve.
  3. interpret data.
  4. calculate an unknown concentration of glucose using a calibration curve.
  5. extrapolate data points on a graph.
  6. calculate initial rate using data.
  7. make predictions using data.

Procedures

Instructional Strategy

This module will utilize the process of inquiry. Students will gather and interpret data. Using their data, they will formulate their own conclusions.

Before starting this module, the teacher should make a presentation using vials that contain different concentrations of glucose solution combined with reagent. The class should brainstorm ideas concerning the cause of the different shades of color. The class should discuss methods of testing their hypotheses.

The school nurse should come into the classroom to discuss blood glucose with the students. The normal blood glucose range in plasma or serum is 70 - 105 mg/dL for fasting adults. For whole blood the range is 60 - 95 mg/dL. Increased levels of blood glucose can be associated with diabetes mellitus, hyperactivity of the thyroid, pituitary or adrenal glands. Decreased levels of blood glucose have been observed in cases of insulin overdose, insulin secreting tumors, hypopituitarism, hypoadrenalism and conditions that interfere with glucose absorption. These diseases substantiate the importance of accurately measuring blood glucose levels. Students will be given the opportunity to have their blood glucose level measured.

Students will be given instruction on how to use a computer spreadsheet. Using these types of program, the students will graph and calculate the average absorbance, slope and initial rate of reaction.

Following are three teacher-oriented laboratory exercises. In Appendices A, B and C are the equivalent student labs. The following investigations use Glucose Reagent Enzymatic-500 nm kit. The product number is 80038. The kit may be purchased from:

Reagents Application, Inc
8225 Mercury Court
San Diego, CA 92111-1203
(800) 438-6100

Many schools do not have a spectrophotometer available to use. There is an equipment loan program sponsored by a Howard Hughes Medical Institute grant to Washington State University. For more specific information contact the Program in Biology at (509) 335-8528.

 


Scan Glucose Reaction To Find Optimum Wavelength

Time: 100 minutes

Materials Needed:

1 Small Beaker
28 Cuvettes
10 mL 300 mg/dL Glucose Solution
28 Goggles
28 Parafilm Squares
2 Pipettes
28 Large Pipette Tips
14 Small Pipette Tips
1 Spectrophotometer
1 Small Test Tube
50 mL Trinder Reagent
1 Vortex Apparatus
  1. Prepare the Trinder reagent as stated in the kit. Place the reagent in the beaker. Glucose solution needs to be placed in the test tube. Keep the reagent and glucose solution refrigerated.
  2. Discuss the glucose and Trinder reagent reaction with the students.
  3. Demonstrate proper pipetting techniques.
  4. Define absorbance: amount of radiation absorbed. The amount of radiation absorbed by the sample being analyzed is a measure of its' concentration.
  5. Describe how a spectrophotometer works. It measures the absorbance of radiation through a sample by monitoring the ratio of the intensity of the radiation with a sample in the path of the beam to the intensity of the radiation when no sample is present. Demonstrate how to use the spectrophotometer. Discuss the importance of the sample blank.
  6. Explain to students how to graph their data.
  7. Use Appendix A.

 

Calibration Curve Using Spectrophotometer

Time: 100 minutes

Materials Needed:

11 Small Beakers
84 Cuvettes
  Deionized Water
10 mL 300 mg/dL Glucose Solution
28 Goggles
11 Large Parafilm Squares
84 Small Parafilm Squares
  Pipettes
  Large Pipette Tips
  Small Pipette Tips
  Spectrophotometer
  Trinder Reagent
  Vortex Apparatus

 

  1. Prepare concentrations of the glucose solution as follows:
    glucose
    concentration
    deionized
    water
      300 mg/dL
    glucose solution
    50 mg/dL 250 uL + 50 uL
    60 mg/dL 240 uL + 60 uL
    70 mg/dL 230 uL + 70 uL
    80 mg/dL 220 uL + 80 uL
    90 mg/dL 210 uL + 90 uL
    100 mg/dL 200 uL + 100 uL
    110 mg/dL 190 uL + 110 uL
    120 mg/dL 180 uL + 120 uL
    130 mg/dL 170 uL + 130 uL
    140 mg/dL 160 uL + 140 uL
    150 mg/dL 150 uL + 150 uL
  2. Keep glucose solution in the refrigerator when not in use.
  3. Students will incubate their cuvettes for 15 minutes.
  4. Students are to calibrate to zero the spectrophotometer before each measurement.
  5. Use Appendix B.

Temperature Effects

Time:

100 minutes

Materials Needed:

14 Beakers
70 Cuvettes
5 mL Glucose Solution
28 Goggles
  Boiling water
21 Ice Cubes
49 Paraffin Squares
  Pipettes & Tips
  Spectrophotometer
7 Stopwatches
42 Test Tubes
7 Test Tube Racks
50 mL Trinder Reagent
  Vortex Apparatus
  1. Caution students about being careful when using the boiling water.
  2. Explain to students that immediately after pipetting the glucose solution into the cuvette, one student must start the stopwatch and be the timer.
  3. Remind students how to find the average absorbance.
  4. Explain initial rate to the students.
  5. Use Appendix C.

Class Environment

Groups

The class should be divided into groups of four. Students will be given jobs in order to complete the investigation. The jobs are as follows: timekeeper, data collector, leader and pipetter. Students will trade jobs before each investigation.

Data Collection

Students will use their lab worksheet to enter their data. All students are expected to complete their lab write-up.

  1. Students will be collecting absorbance data using the spectrophotometer.
  2. Students will be graphing absorbance vs. wavelength.
  3. Students will be graphing absorbance vs. concentration.
  4. Students will be graphing absorbance vs. time.
  5. Students will calculate the initial rate using their data.

 

Evaluation

Laboratory Worksheets-See Appendices B & C
Quiz-See Appendices D and E

Extensions

Unknown Concentration of Glucose

Students could be given an unknown concentration of glucose and could be challenged to determine its concentration.

Field Trip

Students could tour a local blood analysis laboratory. Prior to the visit, students should prepare questions to be asked of the laboratory technicians.

Data, Graphing & Mathematics

Working with the mathematics teachers, students can integrate science and mathematics. They can then use their data to study concepts in mathematics such as graphing, linear relationships using the formula y = m*x + b, slope, and y-intercept.

Guest Speakers

During the module, an engineering professor and/or graduate student could visit the students and talk about the experiments and potential careers in engineering or technology.


Appendix A

Name ________________
Science_______________
Date _________________
Worksheet# ___________

SCAN GLUCOSE REACTION TO FIND OPTIMUM WAVELENGTH

PURPOSE:

THE PURPOSE OF THIS INVESTIGATION IS TO FIND THE OPTIMUM WAVELENGTH TO SCAN GLUCOSE REACTION.

MATERIALS:

CUVETTES
GLUCOSE SOLUTION (300 mg/dL)
GOGGLES
PARAFILM SQUARES
PIPETTES & TIPS
SPECTROPHOTOMETER
TRINDER REAGENT
VORTEX APPARATUS

PROCEDURE:

  1. WRITE A PROBLEM STATEMENT FOR THIS ACTIVITY.

    __________________________________________________________________

    __________________________________________________________________

  2. IN ORDER TO ZERO THE SPECTROPHOTOMETER, USE 1500 microliters OF TRINDER REAGENT AS A SAMPLE BLANK.
  3. PIPETTE 10 microliters OF 300 mg/dL GLUCOSE INTO A CUVETTE.
  4. ADD 1500 microliters OF TRINDER REAGENT AND VORTEX (MIX).
  5. INCUBATE SAMPLE FOR 15 MINUTES.
  6. PRIOR TO TESTING, MAKE SURE THERE ARE NO BUBBLES AND WIPE OFF ANY FINGERPRINTS.
  7. MEASURE ABSORBANCE STARTING WITH 420 nm TO 580 nm IN 10 nm INTERVALS. ZERO AFTER EACH MEASUREMENT USING THE SAMPLE BLANK.
  8. RECORD DATA IN A DATA TABLE.
  9. GRAPH WAVELENGTH vs. ABSORBANCE.

DATA:

WAVELENGTH (nm) ABSORBANCE UNIT
420 _
430 _
440 _
450 _
460 _
470 _
480 _
490 _
500 _
510 _
520 _
530 _
540 _
550 _
560 _
570 _
580 _

AFTER YOU ADDED THE REAGENT TO THE GLUCOSE SOLUTION, WAS THERE A CHEMICAL REACTION? ______
EXPLAIN YOUR ANSWER USING A COMPLETE SENTENCE.

___________________________________________________________________

___________________________________________________________________

DEFINE ABSORBANCE IN YOUR OWN WORDS.

___________________________________________________________________

___________________________________________________________________

GRAPH:

(Draw one.)

 

 

 

 

 

 

 

CONCLUSION (ANSWER THE PROBLEM STATEMENT):

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________


Appendix B

Name _________________
Science ________________
Date __________________
Worksheet# ____________

CALIBRATION CURVE USING SPECTROPHOTOMETER

PURPOSE:

THE PURPOSE OF THIS INVESTIGATION IS TO CALIBRATE THE CURVE OF GLUCOSE CONCENTRATION VS. ABSORBANCE.

MATERIALS:

CUVETTES
GLUCOSE SOLUTIONS
GOGGLES
PARAFILM
PIPETTES & TIPS
SPECTROPHOTOMETER
TRINDER REAGENT
VORTEX APPARATUS

PROCEDURE:

  1. WRITE A PROBLEM STATEMENT FOR THIS ACTIVITY.

    ___________________________________________________________________

    ___________________________________________________________________

  2. IN A CUVETTE, PIPETTE 20 microliters OF 50 mg/dL GLUCOSE.
  3. ADD 1500 microliters OF TRINDER REAGENT TO THE CUVETTE AND VORTEX.
  4. INCUBATE THE CUVETTE FOR 15 MINUTES.
  5. ZERO THE SPECTROMETER USING 1500 microliters OF TRINDER REAGENT AS A SAMPLE BLANK.
  6. USING THE SPECTROPHOTOMETER, FIND THE ABSORBANCE OF THE REACTION AT 500 nm.
  7. RECORD DATA IN A DATA TABLE.
  8. REPEAT STEPS 1-6 USING THE DIFFERENT GLUCOSE CONCENTRATIONS.
  9. GRAPH CONCENTRATION VS. ABSORBANCE

DATA:

GLUCOSE (mg/dL) ABSORBANCE (500 nm)
50 _
60 _
70 _
80 _
90 _
100 _
110 _
120 _
130 _
140 _
150 _

LOOK AT THE CUVETTES STARTING FROM THE LOWEST TO HIGHEST CONCENTRATION. DESCRIBE WHAT YOU OBSERVE.

___________________________________________________________________

___________________________________________________________________

GRAPH:

(Draw one.)

 

 

 

 

CONCLUSION (ANSWER THE PROBLEM STATEMENT):

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________


Appendix C

Name ________________
Science- ______________
Date _________________
Worksheet# ___________

WHAT ARE THE EFFECTS OF TEMPERATURE ON THE TRINDER REACTION?

MATERIALS:

BEAKERS CUVETTES
GLUCOSE SOLUTION GOGGLES
HOT WATER ICE
PARAFFIN SQUARES PIPETTES & TIPS
SPECTROPHOTOMETER TEST TUBES
TEST TUBE RACK TRINDER REAGENT
VORTEX APPARATUS

PROCEDURE:

  1. MAKE A SAMPLE BLANK USING 1500 microliters OF TRINDER REAGENT. COVER WITH A PARAFFIN SQUARE.
  2. STATE THE PROBLEM THAT YOU WILL BE INVESTIGATING. ___________________________________________________________________

    ___________________________________________________________________

  3. WRITE YOUR HYPOTHESIS TO THE PROBLEM.

    ___________________________________________________________________

    ___________________________________________________________________

  4. LABEL THE TEST TUBES AS FOLLOWS:
    C-G: COLD GLUCOSE
    C-R: COLD REAGENT
    W-G: WARM GLUCOSE
    W-R: WARM REAGENT
    H-G: HOT GLUCOSE
    H-R: HOT REAGENT

    PLACE THE TEST TUBES IN THE RACK.

  5. IN EACH OF THE GLUCOSE TEST TUBES, PIPETTE 100 microliters. COVER EACH TEST TUBE WITH A PARAFFIN SQUARE.
  6. IN EACH OF THE REAGENT TEST TUBES, PIPETTE 5000 microliters. COVER EACH TEST TUBE WITH A PARAFFIN SQUARE.
  7. PREPARE AN ICE BATH BY PLACING 3 ICE CUBES IN A BEAKER AND ADDING WATER. PLACE THE C-G AND C-R TEST TUBES IN THE ICE BATH FOR 10 MINUTES.
  8. WHILE YOU ARE WAITING THE TEN MINUTES, PIPETTE 1500 microliters OF THE WARM REAGENT INTO A CUVETTE. PIPETTE 20 microliters OF THE WARM GLUCOSE INTO THE CUVETTE. USE THE STOPWATCH TO TIME THE REACTION. VORTEX THE CUVETTE.
  9. MEASURE THE ABSORBANCE USING THE SPECTROPHOTOMETER EVERY 20 SECONDS FOR TWO MINUTES.
  10. RECORD YOUR DATA IN THE DATA TABLE.
  11. REPEAT STEPS #8-10 SO THAT YOU HAVE 3 TRIALS.
  12. PREPARE A HOT WATER BATH BY CAREFULLY POURING HOT WATER INTO A BEAKER. PLACE H-G & H-R TEST TUBES IN THE HOT WATER BATH. LET THEM SIT IN THERE FOR 10 MINUTES.
  13. REPEAT STEPS #8-11 USING C-G & C-R TEST TUBES.
  14. REPEAT STEPS #8-11 USING H-G & H-R TEST TUBES.

DATA TABLE:

COLD
TIME
(SEC)
  ABSORBANCE
  TRIAL 1 TRIAL 2 TRIAL 3 AVERAGE
0 _ _ _ _
20 _ _ _ _
40 _ _ _ _
60 _ _ _ _
80 _ _ _ _
100 _ _ _ _
120 _ _ _ _

 

 

WARM
TIME
(SEC)
  ABSORBANCE
  TRIAL 1 TRIAL 2 TRIAL 3 AVERAGE
0 _ _ _ _
20 _ _ _ _
40 _ _ _ _
60 _ _ _ _
80 _ _ _ _
100 _ _ _ _
120 _ _ _ _

 

 

HOT
TIME
(SEC)
  ABSORBANCE
  TRIAL 1 TRIAL 2 TRIAL 3 AVERAGE
0 _ _ _ _
20 _ _ _ _
40 _ _ _ _
60 _ _ _ _
80 _ _ _ _
100 _ _ _ _
120 _ _ _ _

TO FIND THE AVERAGE, USE THE FOLLOWING FORMULA:
AVERAGE= (TRIAL 1 + TRIAL 2 + TRIAL 3) / 3

GRAPH ABSORBANCE VS TIME FOR ALL 3 TEMPERATURES.

COLD TEMPERATURE GRAPH:

(Draw one.)

 

 

 

 

WARM TEMPERATURE GRAPH:

(Draw one.)

 

 

 

 

HOT TEMPERATURE GRAPH:

(Draw one.)

 

 

 

 

TO FIND THE INITIAL RATE, USE THE FOLLOWING EQUATION:
RATE = (ABSORBANCE #2 - ABSORBANCE # 1) / (TIME #2 - TIME #1)

COLD RATE = ________
WARM RATE = ________
HOT RATE = ________

LOOKING AT THE DATA, HOW DOES TEMPERATURE AFFECT THE TRINDER REACTION?

___________________________________________________________________

___________________________________________________________________
HOW DOES YOUR HYPOTHESIS COMPARE WITH YOUR FINDINGS?

___________________________________________________________________

___________________________________________________________________
WHY DO YOU THINK SOME REACTIONS ARE FASTER THAN OTHERS?

___________________________________________________________________

___________________________________________________________________


Appendix D

Name ________________
Science- ______________
Date ________________

Glucose Analysis Quiz

Use the following graph to answer Questions #1 & #2.

 

*INSERT A GRAPH OF ABSORBANCE VS WAVELENGTH

 

 

  1. Name the wavelength that should be utilized to find absorbance using the spectrophotometer. _______
  2. Explain your answer to question Number 1.

    ___________________________________________________________________

    ___________________________________________________________________

    Use the following graph to answer Questions #3 & #4.


    *INSERT A GRAPH OF ABSORBANCE VS CONCENTRATION





  3. FIND THE ABSORBANCE FOR 8O mg/dL glucose solution.

    __________

  4. CALCULATE THE SLOPE OF THIS LINE. _________________
  5. A SIXTH GRADER ASKS WHAT YOU HAVE BEEN DOING IN CLASS. EXPLAIN WHAT YOU HAVE BEEN DOING USING THE SPECTROPHOTOMETER AND HOW ENGINEERING IS RELATED TO THESE ACTIVITIES.

    ___________________________________________________________________

    ___________________________________________________________________

    ___________________________________________________________________

    ___________________________________________________________________

    ___________________________________________________________________

  6. DESCRIBE HOW YOU WOULD CHANGE THE RATE OF REACTION.

    ___________________________________________________________________

    ___________________________________________________________________


Appendix E

Name _______________
Science- _____________
Date _______________

Glucose Analysis Quiz

Use the following graph to answer Questions #1 & #2.

 

 

 

 

 

  1. Name the wavelength that should be utilized to find absorbance using the spectrophotometer. 500 nm
  2. Explain your answer to question Number 1.

    YOU WANT TO SEE THE WAVELENGTH THAT ABSORBS THE MOST. LOOKING AT THE GRAPH YOU NOTICE THAT 500 nm ABSORBED THE MOST.

    Use the following graph to answer Questions #3 & #4.

     

     

     

     

  3. FIND THE ABSORBANCE FOR 8O mg/dL glucose solution.
    0.16 absorbance units
  4. CALCULATE THE SLOPE OF THIS LINE. 0.002 abs/mg/dL
  5. A SIXTH GRADER ASKS WHAT YOU HAVE BEEN DOING IN CLASS. EXPLAIN WHAT YOU HAVE BEEN DOING USING THE SPECTROPHOTOMETER AND HOW ENGINEERING IS RELATED TO THESE ACTIVITIES.
    A spectrophotometer measures absorbance or the amount of light absorbed by the molecules in the solution when a beam of light passes through it. The reaction between glucose and Trinder reagent causes a pink dye to form which we measured using the spectrophotometer. The rate of reaction (or how fast the reaction takes place) can be changed by changing the temperature. Different wavelengths absorb different amounts of light.
  6. DESCRIBE HOW YOU WOULD CHANGE THE RATE OF REACTION.
    You could change the rate of reaction by changing the temperature, stirring or adding an enzyme.

STUDENT EVALUATION

Activity ___________________ Science Class __________

Your teacher is helping with a project to design science lessons. You can help with the project by answering a few questions about the lesson you have just finished. Please remember that the questions are about the lesson, not the teacher. Do not put your name on this paper.

Check each statement just once to tell us how you agree or disagree with the statement.

  1. I learned something about engineering and science that I didn't know before.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree
  2. I like being able to do science activities, rather that just reading about them.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree
  3. I could easily understand the science lesson.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree
  4. I would have liked it better, if the teacher had just told us about the lesson instead of having us do it.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree
  5. The lesson was well discussed when we completed it.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree
  6. This type of lesson makes me want to follow-up with more of my own investigations.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree
  7. This kind of science lesson makes me interested in engineering.
    _____ strongly agree
    _____ agree
    _____ disagree
    _____ strongly disagree