ENZYMES: Temperature, pH, and specificity.

Enzymes: Temperature, pH,
and Specificity
Hands-on labs, inc.
Version 42-0054-00-01

Review the safety materials and wear goggles when
working with chemicals. Read the entire exercise
before you begin. Take time to organize the materials
you will need and set aside a safe work space in
which to complete the exercise.

Experiment Summary:

Students will learn how enzymes act as catalysts to
lower the activation energy required for a reaction
to proceed in both catabolic and anabolic processes.
Students will study competitive inhibition, negative
feedback, and enzyme specificity using lactase on
various substrates. They will study the effects of
temperature and pH on the ability of lactase to break
down lactose.

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Experiment

Objectives
● To learn how enzymes work

● To understand enzyme specificity

● To relate enzyme activity to temperature, pH, and concentration

● To understand the role of enzymes in digestion of lactose

Time Allocation: 3 hours

Safety: So that you understand the proper procedures to use when handling, pouring, heating,
etc. chemicals, if you have not already done so, read the section in the introduction to this Lab
Manual titled “Laboratory Equipment and Techniques” before beginning this experiment. Also,
always wear goggles when handling chemicals, and also use gloves when directed to do so.

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Experiment Enzymes Temperature pH specificity

materials

Materials
FRoM:

lABEl
oR BoX/

BAg:
QTy iTEM DESCRiPTioN:

Student
Provides

10
1

Bathroom or facial tissues
Freezer

1 10
Milk, 1 cup
Paper, tissue in sheets

1 Oven mitt
1 Scissors
2 Spoons

1
1
1

Sucrose (Table sugar), 2.5 grams
Stove and pan for Hot Water Bath
Water, distilled (1 liter)

From LabPaq 1 Glucose, 20% solution in pipet
24 Glucose test strips
1 Graduated Cylinder, plastic, 50 mL
2 Lactase pills
1 Pencil, marking

10 Pipet, Empty Long Stem
6 Plastic cup, 9 oz

1

Scale-Digital – iMPoRTANT !!! – If you do not perform
the following two steps your scale will not work properly:
1) If present, on the side of the scale underneath the
weighing platform, pull out the small plastic strip which
is attached to a piece of cardboard that protects the scale
during shipping, and 2) Remove the plastic strip between
the battery & connectors, or if the batteries are shrink-
wrapped, the shrink-wrap must be removed.

1 Test-tube-clamp-holder
1 Test-tube-cleaning-brush
1 Test Tube (3), 13 x 100 mm in Bubble Bag
1 Test-tube-rack -6×13-mm
1 Thermometer-in-cardboard-tube
1 Well-Plate -12
1 Gloves, disposable – pair
1 Rod, Stirring – glass

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Experiment EnzymEs TEmpEraTurE pH spEcificiTy

Enzymes 1 pH 11.5, Buffer- 2 mL in Pipet
1 pH 3.5, Buffer – 2 mL in Pipet
1 pH 5.0, Buffer – 2 mL in Pipet
1 pH 6.8, Buffer – 2 mL in Pipet

Note: The packaging and/or materials in this LabPaq may differ slightly from that which is listed
above. For an exact listing of materials, refer to the Contents List form included in the LabPaq.

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Experiment EnzymEs TEmpEraTurE pH spEcificiTy

DiscussiOn anD rEviEw
When nutrients are broken down into smaller and simpler molecules, energy is released and
these molecules then provide building blocks for the organism. For instance, food consumed is
broken down into individual sugar, amino acid, and/or fatty acid components. These components
are then recombined with other molecules to make proteins, hormones, or other molecules. The
breakdown of large molecules into smaller molecules is called catabolism. The recombining of
molecules to synthesize larger molecules is called anabolism.

All of these reactions require the assistance of a type of protein called enzymes. Enzymes are
catalysts, chemicals that work in the body by speeding up reaction times. Enzymes work by
lowering the amount of energy required to convert molecules from one form to another. The
amount of energy required is called activation energy (EA). Enzymes help lower EA, similar to
helping another person pull a wagon up a hill: it requires less work when assistance is available.
See Figure 1. Enzymes are very specific in that they act by binding to a specific molecule, and alter
its shape so that the reaction is more likely to occur. Without enzymes, it would take much longer
for chemical reactions to occur. All chemical reactions in biological systems require the presence
of enzymes.

Figure 1: Activation energy is lowered by enzymes
Courtesy of Brian Kell

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Enzymes and Their Effect on Chemical Reaction Rates

Proteins are composed of strands of amino acid chains called polypeptides. To create a
3-dimensional active enzyme, this polypeptide is folded, held together by chemical bonds. These
sites physically fit together with another molecule called the substrate or reactant, creating
active sites. This is analogous to a key fitting in a lock. When the enzyme attaches itself to the
substrate molecule, a new temporary molecule is formed, called the enzyme-substrate complex
(ESC). Within the complex, the bonds that need to be broken or formed in the reaction are in close
proximity to the active site. Because the bond between the enzyme’s active site and substrate
causes intermolecular bond strain due to electromagnetic interactions, the bond breaking or
forming of the substrate requires less activation energy. Figure 2 shows the breakdown of a large
molecule into two smaller molecules with the use of an enzyme.

Figure 2: An enzyme functions by fitting in a substrate active site

How the Environment Affects Enzyme Activity

Temperature

Temperature can affect an enzyme by altering its shape. All enzymes have an optimal temperature
at which they function best, which is usually similar to the average temperature of the organism. If
the temperature is much lower than optimum, the reaction may occur at a slower rate. Conversely,
if the temperature is too high, the protein structure can be denatured and rendered inactive, a
nonreversible reaction. Figure 3 illustrates how temperature can affect enzyme activity.

Figure 3: An example of the effect of temperature on enzyme activity. The red
“X” indicates optimal reaction temperature in this scenario.

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Experiment Enzymes Temperature pH specificity

pH

Enzymes also have an optimum pH for activity, usually it is equivalent to the optimum pH for
biological organisms (about 7.4). pH is dependent on the amount of dissolved H+ ions in a solution.
Since pH is a negative logarithmic scale, the higher the amount of H+ ions in a solution, the lower
the pH. The increase or decrease in hydrogen ions can alter the shape of the enzymes by making
or breaking the intra- and intermolecular bonds. This is illustrated in Figure 4.

Figure 4: An example of the effect of pH on enzyme activity. The red
“X” indicates optimal pH in this scenario.

Substrate Concentration

The concentration of both the substrates and enzymes influence the rate of enzymatic reactions.
As the enzyme concentration is increased, there is an increase in the conversion of substrate
to the product. If the enzyme concentration is decreased, the rate at which product is formed
also decreases, because enzymes can only work on the substrates in a 1:1 ratio. Enzymes must
attach to a substrate, alter it, and then release before proceeding to the next substrate. The more
enzymes there are, the faster the reaction will be. When saturation occurs, all of the substrate has
reacted with all of the enzymes, and the reaction halts. See example in Figure 5.

Figure 5: An example of the enzyme concentration and reaction
rate. The red “X” indicates point of saturation in this scenario.

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Experiment Enzymes Temperature pH specificity

Cellular Controlling Processes and Enzymes

Metabolic activities are regulated to proceed in a certain sequence and rate. The genetic code
in a cell determines the order of reactions and the amount of enzyme produced. Three types of
control processes include enzymatic competition, negative feedback, and inhibition.

Enzymatic competition occurs when there are several different enzymes available to combine
with a given substrate. Because enzymes compete with a specific substrate site, each has fewer
chances to interact with the substrate.

Negative feedback controls protein synthesis in the body. When the concentration of products
reaches a certain level, production ceases. This prevents too much synthesis of a product. For
example, in the enzymatic pathway A à B à C à D, each arrow represents an enzyme. A is the
reactant, B and C are intermediate molecules, and D is the end product. When D reaches a certain
concentration, it will block the first enzyme in the pathway.

Inhibition occurs when the operation of enzymes is influenced by the presence of other molecules.
An inhibitor is a molecule that binds to the enzyme and interferes with its ability to form an
enzyme-substrate complex, so the reaction cannot occur.

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Experiment EnzymEs TEmpEraTurE pH spEcificiTy

Exercise 1: Enzyme Specificity
Enzymes are needed to decompose molecules, including sugar molecules called disaccharides
(which contain two sugar molecules) into monosaccharides (single sugar molecules). The most
important monosaccharide is glucose, which is used to produce energy in cellular respiration.
Lactose (milk sugar) is a disaccharide composed of glucose and galactose. Sucrose (table sugar) is
also a disaccharide, composed of fructose and glucose.

lactase is the enzyme that is responsible for the breakdown of lactose into galactose and glucose.
Certain individuals lack the ability to produce lactase, which makes them “lactose intolerant.” If
lactose is consumed but cannot be broken down, it causes indigestion. When a lactose intolerant
individual consumes lactase, it will digest lactose into glucose and galactose. In this exercise,
lactase will be used in an attempt to break down the disaccharides lactose and sucrose.

procedure
1. Before beginning, set up a data table similar to the Data Table 1 in the Lab Report Assistant

section to for record your observations.

Prepare a 5% sucrose solution

2. Using the digital scale, weigh 2.5 g of sucrose.

3. Place the sucrose into one of the plastic cups provided in your LabPaq.

4. Label the cup “5% Sucrose” with the marking pencil.

5. Measure 50 mL of distilled water with the graduated cylinder and add the water to the 2.5 g
of sucrose in the “5% Sucrose” cup.

6. Mix with a stirring rod until the sucrose dissolves.

7. Clean the stirring rod thoroughly and dry it.

Prepare the lactase solution

8. Retrieve one lactase pill and another plastic cup.

9. Crush the lactase pill between two spoons over the plastic cup.

10. Place the crushed pill into the plastic cup.

11. Label the cup “Lactase Solution.”

12. Measure 200 mL of distilled water with the graduated cylinder and pour it into the plastic cup
containing the crushed lactase pill.

13. Mix with a stirring rod until dissolved.

14. Clean the stirring rod thoroughly and dry it.

15. Measure 50 mL of milk with the graduated cylinder and pour it into a clean plastic cup.

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Experiment EnzymEs TEmpEraTurE pH spEcificiTy

16. Clean the graduated cylinder thoroughly and dry it.

17. Obtain the well plate.

18. Label five of the wells a through e using the marking pencil, and follow the directions in the
steps below for the contents of the wells.

Well Plate
label Contents: see the procedures below

a 3 drops sucrose + 3 drops dH2O
b 3 drops milk + 3 drops H2O
c 3 drops sucrose + 3 drops lactase
d 3 drops milk + 3 drops lactase
e 3 drops glucose + 3 drops distilled water

Figure 6: Well labels

19. Use a clean, long-stemmed pipet to add three drops of the sucrose solution to well a.

Note: Keep this pipet in the sucrose solution cup to be used later in the exercise.

20. Use a new, clean, long-stemmed pipet to add three drops of distilled water to well a.

Note: Keep this pipet in the rinsed out graduated cylinder to be used later in the exercise.

21. Using a clean, long-stemmed pipet, add three drops of milk and three drops of distilled water
to well b using the distilled water pipet.

Note: Keep the milk pipet in its cup.

22. Add three drops of the sucrose solution and three drops of the lactase solution to wellc using
the sucrose and lactase pipets.

Note: Keep the lactase solution pipet in its cup.

23. Add three drops of milk and three drops of the lactase solution to well d using the milk and
lactase pipets.

24. Using the pipet containing the 20% glucose solution, add three drops of the glucose solution
and three drops of distilled water to well e using the distilled water pipet.

25. While waiting for the reaction to occur (wait 5 minutes), obtain five glucose strips.

26. Label them a, b, c, d, and e using the marking pencil. Refer to Figure 7.

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Figure 7: Label glucose strips for each well

iMPoRTANT: Complete the following steps as instructed:

27. Dip a test strip into the solution in well a for 5 seconds.

28. Gently blot the side of the test strip on apiece of tissue to remove excess solution. If the strip
is not blotted, the glucose concentration will not be accurate—it will be too concentrated.

29. Wait 30–60 seconds for the color to develop, and then compare the test strip to the color
chart shown in Figure 8.

you must take a reading of the test strip at least no later than the 60-second mark. if you wait
longer, the reading will be inaccurate.

Figure 8: Color comparison chart for glucose test strips.

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30. Record the glucoseconcentration for well a in Data Table 1.

Note: A zero reading for this measurement is expected.

31. Test the glucose concentration in the remaining wells labeled b–e. Repeat the procedures in
Steps 27–29, using one new test strip per well.

32. Record the glucose concentrations of each well in Data Table 1.

Note: A zero reading for some measurements is expected.

33. Save the sucrose solution, lactase solution, and milk for the next two exercises.

34. Keep the pipets in their corresponding liquids so they are not contaminated with the other
solutions.

35. Rinse the contents of the well plate down the drain and then thoroughly clean and dry the
well plate for use in the next exercise.

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Exercise 2: Enzymes and Temperature
Temperature affects the movement of molecules—higher temperatures cause molecules to move
faster. If molecules move faster, enzymes are able to connect with substrates more quickly and
bind to them. However, higher temperatures may also destroy enzymes. Enzymes are protein
molecules formed from amino acid chains bound together by hydrogen bonds. Hydrogen bonds
are easily formed and broken. Therefore, when the temperature changes, these bonds can be
changed, stretched, or broken. When temperature increases, the molecules move faster and the
collisions between them become more forceful, causing the bonds to break and water molecules
to fly off the surface, creating steam. This can change the shape of the protein’s active site. If this
change is too drastic, it can affect the enzyme’s ability to bind to a substrate.

prOcEDurE
1. Before beginning, set up a data table similar to the Data Table 2 in the Lab Report Assistant

section to record your observations.

2. Prepare a boiling water bath:

a. Fill a pot with water about 5 to 6 cm deep.

b. Place the pot onto the stovetop.

c. Place the metal test tube rack into the pot.

d. Bring the water to a boil.

3. Label three 13 x 100 mm test tubes with the black marking pencil as indicated in Figure 9:

Test Tube
label Contents Condition

a 5 mL lactase hot water temperature
b 5 mL lactase cold water temperature
c 5 mL lactase room temperature

Figure 9: Test tube labels: see above for preparation of the contents

4. Stir the lactase solution (from Exercise 1) with the lactase solution pipet.

5. Use the pipet to squeeze 5 mL of the lactase solution into the graduated cylinder.

6. Pour the 5 mL of lactase solution into test tube a.

7. Using the test tube clamp, carefully place test tube a into the test tube rack in the boiling
water bath.

8. Record the time that the test tube was placed into the water bath into Data Table 2.

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9. Place test tubes b and c in separate clean plastic cups to hold them upright.

10. Measure and pour 5 mL of lactase solution into test tube b, and place the cup with the test
tube in the freezer.

11. Measure and pour 5 mL of lactase solution into test tube c, and place the cup with the test
tube on the counter at room temperature.

12. Leave the test tubes a and b at the different temperatures for 15 minutes.

During the 15-minute wait time

13. Measure the room temperature solution by placing the thermometer into test tube c for 1
minute.

14. Record the temperature in the lab report.

15. Remove, wash, and dry the thermometer.

At the end of the 15-minute time period

16. Carefully place the thermometer in test tube a (the boiling water bath) for 1 minute.

17. Record the temperature in lab report.

18. Remove, wash, and dry the thermometer.

19. Place the thermometer in test tube b (located in the freezer) for 1 minute.

20. Record the temperature into the lab report.

21. Remove, wash, and dry the thermometer.

22. Label the three wells in the well plate: a, b, and c as illustrated in Figure 10.

Figure 10: Well plate set up for temperature test.

23. Prepare the well plate by adding three drops of milk to three different wells leaving one empty
well between the milk wells.

24. Label three, clean long-stem pipets: a, b, and c.

25. Retrieve 12 glucose test strips. Label four strips a, four strips b, and four strips c.

26. Use the test tube holder clamp to carefully remove test tube a from the rack in the boiling
water bath.

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27. Place test tube a in a plastic cup.

28. Remove the test tube b from the freezer. If the solution is too solid to draw into a pipet, wait
30–60 seconds for the solution to thaw.

29. Using pipet a, pull a small amount of lactase solution out of test tube a. Add three drops of
the solution to well a.

30. Using pipet b, pull a small amount of lactase solution out of test tube b. Add three drops of
the solution to well b.

31. Using pipet c, pull a small amount of lactase solution out of test tube c. Add three drops of
the solution to well c.

32. Wait 5 minutes for reactions within the wells to complete.

iMPoRTANT: Complete the following steps as instructed:

33. Dip a test strip into the solution in well a for 5 seconds.

34. Blot the test strip with a piece of tissue to remove excess solution.

35. Wait 30–60 seconds for the color to develop, and then compare the test strip to the color
chart shown in Figure 8. Record the glucose concentration into Data Table 2.

you must take a reading of the test strip at least no later than the 60-second mark. if you wait
longer, the reading will be inaccurate.

36. Test the glucose concentration in the remaining wells b and c, following the same instructions
given for Steps 33-35. Use one new test strip per well. Record the glucose concentration into
Data Table 2.

37. After 10 minutes, dip a new glucose test strip into each of the three wells. Record the glucose
concentration into Data Table 2.

38. After 15 minutes, dip a new glucose test strip into each of the three wells. Record the glucose
concentration into Data Table 2.

39. After 20 minutes, dip a new glucose test strip into each of the three wells. Record the glucose
concentration into Data Table 2.

40. Thoroughly clean and dry the well plate so it is ready for the next exercise.

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Experiment EnzymEs TEmpEraTurE pH spEcificiTy

Exercise 3: Enzymes and pH
As mentioned in Exercise 2, the peptide bonds in a protein (bonds between amino acids) are
largely responsible for the shape of the protein. Changes in pH can alter the ionization (charges
created by the donation or acceptance of electrons) of parts of the amino acids. If the charges
on the amino acids are altered by a change in pH, hydrogen bonding within the protein molecule
changes and the overall protein molecule reconfigures its shape. This can alter its effectiveness or
even render it useless if the change is enough to denature the enzyme. Amylase, found in saliva,
has an optimal pH of 7.4, whereas pepsin from the stomach functions optimally at a pH of 1.5 to
2.0. In this exercise, you will learn how lactase functions at various pH values.

prOcEDurE
1. Before beginning, set up a data table similar to the Data Table 3 in the Lab Report Assistant

section to for record your observations.

2. Place the well plate onto your work surface.

3. Label four wells a , b, c, and d. Leave an empty well between each labeled well.

Wells Contents – see the procedures below

a 2 drops buffer pH 3.5 + 2 drops lactase + 2 drops milk
b 2 drops buffer pH 5 + 2 drops lactase + 2 drops milk
c 2 drops buffer pH 6.8 + 2 drops lactase+ 2 drops milk
d 2 drops buffer pH 11.5. + 2 drops lactase+ 2 drops milk

Figure 11: Wells a–d

4. Put on your gloves. You must wear them during this exercise.

5. Use scissors to cut off the tips of the pipets that contain the pH solutions.

6. Set the pipets in a clean plastic cup, bulb-end down.

7. Put two drops of pH 3.5 buffer into well a.

8. Put two drops of pH 5 buffer into well b.

9. Put two drops of pH 6.8 buffer into well c.

10. Put two drops of pH 11.5 buffer into well d.

11. Add two drops of the lactase solution to wells a through d.

12. Add two drops of milk to each of the wells a through d.

13. Wait 10 minutes for reactions to occur.

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14. During the 10-minute waiting period, label four glucose test strips a, b, c, and d.

iMPoRTANT: Complete the following steps as instructed:

15. Dip a test strip into the solution in well a for 5 seconds.

16. Blot the test strip with a piece of tissue to remove excess solution.

17. Wait 30–60 seconds for the color to develop, and then compare the test strip to the color
chart shown in Figure 8.

18. You must take a reading of the test strip at least no later than the 60-second mark. If you wait
longer, the reading will be inaccurate. Record the glucose concentration into Data Table 3.

19. Test the glucose concentrations in the remaining wells b–d, following the same instructions
given for Steps 15–18.; use a new test strip per well.

20. Record the glucoseconcentration in Data Table 3.

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Experiment EnzymEs TEmpEraTurE pH spEcificiTy

Enzymes
Below is a listing which will help you to prepare for the quiz and lab on this material.

CONTENT TO KNOW:

I. ENZYME FUNCTION –

• Enzymes are biological CATALYSTS
• Catalysts are things which speed up the rates of reactions
• Enzymes are re-usable; they are not used up in the reaction itself

II. ENZYME STRUCTURE –

• Enzymes are PROTEINS
• Building blocks (sub-units) of proteins are amino acids; therefore the

subunits of enzymes are also amino acids
• ACTIVE SITES – the region of the enzyme which fits the substrate
• SUBSTRATE – the molecule(s) to be worked upon by the enzyme
• Enzyme-Substrate Complex – this is formed when the enzyme and

substrate are bound together; see picture below
• Names of enzymes often end in ASE; “ase” is added to the substrate

name;
 Example: Amylase – the enzyme that breaks down

STARCH

Click HERE for a picture of an enzyme

III. FACTORS AFFECTING ENZYME FUNCTION –

The shape of the protein can be changed by high heat or a change in pH – this is due to
the fact that enzymes have a specific 3 dimensional shape held together by hydrogen
bonds and other interactions between the amino acids;

• DENATURE – to denature an enzyme (protein) means to change its
shape by high heat or pH; when the shape changes the ability of the
enzyme to work is also changed

• OPTIMUM TEMPERATURE OR OPTIMUM pH – the temperature or
pH at which the enzymes functions the best (optimally)

 Be sure that you can identify the optimum pH,
optimum temperature, and maximum velocity on
the graphs below

Click HERE for graphs

 Substrate Concentration & Enzyme Reaction Rate – Note that in the
bottom figure, the velocity cannot increase beyond a certain substrate
concentration, because all the active sites on the enzymes are filled
already; it cannot go any faster once all the enzymes are already working

 Reaction Rate vs. Temperature – all enzymes have a temperature at
which they function optimally (often body temperature)

 Reaction Rate vs. pH – all enzymes have a pH at which they function
optimally (often neutral pH of 7)

IV. Examples of Enzymes –

• LACTASE – an enzyme which breaks down milk sugar which is called LACTOSE;
 SUBSTRATE for LACTASE is LACTOSE; when lactose is broken

down by lactase, glucose and galactose are produced; (remember,
lactose is a disaccharide, (2 sugar units linked together)

• LIPASE – an enzyme activated in the stomach; also found in saliva

 SUBSTRATE for LIPASE are LIPIDS (aka FATS)

• PEPSIN – an enzyme contained in the stomach; also found in saliva
 SUBSTRATE for PEPSIN are PROTEINS

Note: Since LACTASE breaks down LACTOSE (a disaccharide composed of glucose
and galatctose), we test for the presence of GLUCOSE using glucose test
strips. Remember, if lactose is broken down by the enzyme lactase, then the presence
of glucose will be detected .

Enzymes: Temperature, pH, and Specificity

Hands-on labs, inc. Version 42-0054-00-01

LAB REPORT

PHOTOS – Include THREE digital photos with your lab report, either as separate attachments

to an e-mail or paste into your document.

1. Photo #1 – Ex. #1 – Take a photo of the five glucose strips after dipping,

label them a,b,c,d,e to match the data table #1.

2. Photo #2 – Ex. #2 – Take a photo of the 12 glucose strips after dipping,

label them a,b,c, and the times 5,10,15,20 min. to match the data table #2.

3. Photo #3 – Ex. #3 – Take a photo of the four glucose strips after dipping,

label them a,b,c,d, to match the data table #3.

Exercise 1: Enzyme Specificity

Observations

Data Table 1: Glucose Concentration
WellsConcentration of Glucose
a
b
c
d
e

Experiment

EnzymEs TEmpEraTurE pH spEcificiTy

142

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Questions

A. What determines a person’s ability to digest lactose?

B. Which of the wells showed a positive result for glucose? Explain the results.

C. Explain why testing for glucose is used to determine the activity of the enzyme lactase.

D. Explain the experimental conditions for the five different wells.

Exercise 2: Enzymes and Temperature

Observations

Data Table 2: Presence of glucose in wells indicating lactase activity at various temperatures
WellTime (min)Concentration of Glucose

a

5
10
15
20

b

5
10
15
20

c

5
10
15
20

Questions

A. What happens when an enzyme is boiled? Is this effect reversible?

C. Based on your experiment results, what is the optimal temperature for lactase function?

D. Explain what happens as far as the effectiveness of the enzyme at the freezing temperature. Can this effect be overcome when the temperature rises?

Exercise 3: Enzymes and pH

Observations

Data Table 3: Glucose in wells a-d indicates enzyme activity at various pH levels
WellpHConcentration of Glucose
a3.5
b5.0
c6.8
d11.0

Questions

A. Graph the data placing glucose concentrations on the y-axis and the pH values on the x-axis.

B. What was the effect of pH on the enzyme lactase? Is this true for all enzymes?

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Take a photo of the five glucose strips after dipping,

label them a,b,c,d,e to match the data table #1.

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Take a photo of the 12 glucose strips after dipping,

label them a,b,c, and the times 5,10,15,20 min. to match the data table #2.

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Take a photo of the four glucose strips after dipping,

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ose Conce

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t

r

a

tion

W

ells

Conce

n

t

r

a

tion

of Glu

c

ose

a

b

c

d

e

Experiment

EnzymEs TEmpEraTurE pH spEcificiTy

14

2

©Hands-On Labs, Inc.

www.LabPaq.com

Enzymes: Temperature, pH, and Specificity

Hands-on labs, inc. Version 42-0054-00-01

LAB REPORT

PHOTOS – Include THREE digital photos with your lab report, either as separate attachments

to an e-mail or paste into your document.

1. Photo #1 – Ex. #1 – Take a photo of the five glucose strips after dipping,

label them a,b,c,d,e to match the data table #1.

2. Photo #2 – Ex. #2 – Take a photo of the 12 glucose strips after dipping,

label them a,b,c, and the times 5,10,15,20 min. to match the data table #2.

3. Photo #3 – Ex. #3 – Take a photo of the four glucose strips after dipping,

label them a,b,c,d, to match the data table #3.

Exercise 1: Enzyme Specificity

Observations

Data Table 1: Glucose Concentration

Wells Concentration of Glucose

a

b

c

d

e

Name:_________________

Section: ________________

Date:__________________

Exercise #1 – Enzyme Lab

Photo – Sheet

Wells

Concentration of Glucose / TEST STRIPS

A

B

C

D

E

Exercise #2 – Enzyme Lab

Photo Sheet

Well

Time (Min)

Concentration of Glucose

TEST STRIPS

A

5

10

15

20

B

5

10

15

20

C

5

10

15

20

Exercise #3 – Enzyme Lab

Photo Sheet

Well

pH

Concentration of Glucose

TEST STRIPS

A

3.5

B

5.0

C

6.8

D

11.0

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