Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

CHEM 212 LAB REPORT 3 2025-2026| PORTAGE LEARNING|WITH PROCEDURES, EXPLANATION AND RESULTS, Exams of Biochemistry

Pennsylvania State University - AbingtonBiochemistry

CHEM 212 LAB REPORT 3 2025-2026| PORTAGE LEARNING|WITH PROCEDURES, EXPLANATION AND FINAL RESULTS.

Typology: Exams

2024/2025

Available from 04/29/2025

calleb-kahuro
calleb-kahuro 🇺🇸

5

(5)

1.3K documents

1 / 6

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
CHEM 212 LAB REPORT 3 2025-2026| PORTAGE
LEARNING|WITH PROCEDURES, EXPLANATION
AND FINAL RESULTS.
Experiment #: Lab 3
Title: Enzymatic Activity of Lactase.
Purpose: The purpose and goals of this experiment are 1. Isolate an enzyme. The
student should be able to explain how to isolate an enzyme and be able to isolate
an enzyme in the lab. The student should also be able to explain and perform 2.
Assay enzyme activity spectrophotometrically, 3. Investigate the temperature
effect on enzyme activity. 4. Assess thermal denaturing conditions on enzyme
activity. The student should be able to explain, recall, and perform all these goals
after learning them in the current lab.
Procedure:
•
The isolation of lactase
o Procedure:
▪
Step 1: Put on appropriate lab equipment based on what
solutions and chemicals will be used in the lab that they are
performing. Ex: Gloves, Lab coat, Closed toe shoes, Protective
glasses, etc. Also have the appropriate materials needed for
completion of the lab.
▪
Step 2: Take one pill from a lactase packet. And crush pill into
powder form in a mortar and pestle.
▪
Step 3: Place powder into plastic test tube and add 10 mL of
phosphate buffered saline.
▪
Step 4: Place plastic test tube on vortex machine, place on
machine until solution is fully mixed. Which should be around
30 seconds to 1 minute.
▪
Step 5: Using a pipette, take 1 mL of solution and place into
microcentrifuge tube and place into centrifuge.
▪
Step 6: Set to 10,000 revolutions per minute, set timer for a
minute. Make sure there is a counterbalance in centrifuge for
proper spinning.
▪
Step 7: Remove liquid by setting pipette 500 mL, then place
liquid in tube labeled extract.
•
Initial qualitative lactase activity assay
o Procedure:
▪
Step 1: Put on appropriate lab equipment based on what
solutions and chemicals will be used in the lab that they are
performing. Ex: Gloves, Lab coat, Closed toe shoes, Protective
glasses, etc. Also have the appropriate materials needed for
completion of the lab.
▪
Step 2: Pipette 390 mL of phosphate buffer saline to a
pf3
pf4
pf5

Partial preview of the text

Download CHEM 212 LAB REPORT 3 2025-2026| PORTAGE LEARNING|WITH PROCEDURES, EXPLANATION AND RESULTS and more Exams Biochemistry in PDF only on Docsity!

CHEM 212 LAB REPORT 3 202 5 - 2026 | PORTAGE

LEARNING|WITH PROCEDURES, EXPLANATION

AND FINAL RESULTS.

Experiment #: Lab 3 Title: Enzymatic Activity of Lactase. Purpose: The purpose and goals of this experiment are 1. Isolate an enzyme. The student should be able to explain how to isolate an enzyme and be able to isolate an enzyme in the lab. The student should also be able to explain and perform 2. Assay enzyme activity spectrophotometrically, 3. Investigate the temperature effect on enzyme activity. 4. Assess thermal denaturing conditions on enzyme activity. The student should be able to explain, recall, and perform all these goals after learning them in the current lab. Procedure:

- The isolation of lactase o Procedure: ▪ Step 1: Put on appropriate lab equipment based on what solutions and chemicals will be used in the lab that they are performing. Ex: Gloves, Lab coat, Closed toe shoes, Protective glasses, etc. Also have the appropriate materials needed for completion of the lab. ▪ Step 2: Take one pill from a lactase packet. And crush pill into powder form in a mortar and pestle. ▪ Step 3: Place powder into plastic test tube and add 10 mL of phosphate buffered saline. ▪ Step 4: Place plastic test tube on vortex machine, place on machine until solution is fully mixed. Which should be around 30 seconds to 1 minute. ▪ Step 5: Using a pipette, take 1 mL of solution and place into microcentrifuge tube and place into centrifuge. ▪ Step 6: Set to 10,000 revolutions per minute, set timer for a minute. Make sure there is a counterbalance in centrifuge for proper spinning. ▪ Step 7: Remove liquid by setting pipette 500 mL, then place liquid in tube labeled extract. - Initial qualitative lactase activity assay o Procedure: ▪ Step 1: Put on appropriate lab equipment based on what solutions and chemicals will be used in the lab that they are performing. Ex: Gloves, Lab coat, Closed toe shoes, Protective glasses, etc. Also have the appropriate materials needed for completion of the lab. ▪ Step 2: Pipette 390 mL of phosphate buffer saline to a

microcentrifuge tube. ▪ Step 3: Pipette 100 mL of ONPG to solution tube.

▪ Step 9: Once a minute of time is up place 500 mL of sodium carbonate to each tube. ▪ Step 10: Prepare spectrophotometer and place each tube separately and get measurements for all tubes. Make sure to empty and clean cuvette before adding new solution. ▪ Step 11: Write down and record results for further use.

- The assessment of thermal denaturing conditions on lactase activity o Procedure: ▪ Step 1: Put on appropriate lab equipment based on what solutions and chemicals will be used in the lab that they are performing. Ex: Gloves, Lab coat, Closed toe shoes, Protective glasses, etc. Also have the appropriate materials needed for completion of the lab. ▪ Step 2: Create a control solution, by adding 400 mL of PSB and 100mL of ONPG. ▪ Step 3: Create a reaction solution by adding 390 mL of PSB and adding 100 mL of ONPG. ▪ Step 4: Boil enzyme extract for 10 minutes at about 100 degrees C. ▪ Step 5: Let the tube cool down in ice bath for about a minute. ▪ Step 6: Add 10 mL of lactase enzyme extract to reaction tube. ▪ Step 7: Time reaction tube for one minute. ▪ Step 8: Place both control and reaction separately into the spectrophotometer to measure absorbance. ▪ Step 9: Once absorbance has been calculated write down and record results for further use. Data/Results/Calculations: - Initial qualitative lactase activity assay o The color became a yellowish tint after about 2 minutes. - Quantitative spectrophotometric activity assay (lactase vs. control) o The control stayed clear, and the reaction A tube had the same yellowish tint as the tube from the initial lactase activity assay. o Absorbance of control = - .004. o Absorbance of Reaction A =. - The investigation of the effect of temperature on lactase activity o 37 Degrees C ▪ Control: Clear liquid. Absorbance = 0. ▪ Reaction: Brighter yellow color. Absorbance = 0. o 4 degrees C ▪ Control: Clear. Absorbance =. ▪ Reaction: Lite yellow color. Absorbance =.

o Room Temperature: ▪ Control: Clear. Absorbance = - 0. ▪ Reaction: Lite yellow color. Absorbance = 0.

- The assessment of thermal denaturing conditions on lactase activity o Control Absorbance =. o Reaction Absorbance =. o Color-wise reaction tube is very clear compared to other experiment results. Discussion Questions: - Discussion Question 1: The purpose of the ONPG is so that color is visible when there is lactate acting upon it. It is used so that we know the lactate is reactive. - Discussion Question 2: The enzyme activity at 15 degrees C would in my opinion be around the .250 range for absorbance at 420nm. It would be between .209 absorbance and .274 absorbance. - Discussion Question 3: Heating the enzyme to 100 degrees C decreased its activity down to .023 absorbance. Which does denature the enzyme making it less reactive. - Discussion Question 4: The question I would ask is why the absorbance for the 2nd experiment was so much lower than all the other experiments. What would have caused this? Conclusions: The results of the experiment should be 1.) The person performing the experiment should be comfortable extracting lactase enzyme from a powder to a liquid. This is a very important skill for the student to learn in the laboratory because it is a widely used concept. The student should have also learned how making a control and reaction tube is important, because this theoretically give the person performing the lab something to compare the reaction to. The student should have also learned that enzymes act differently at different temperatures. This is true for most things in chemistry, when heat was added to the enzyme its absorbance was greater, when the enzyme was cooled the absorbance was lower and this is due to the reactivity of the enzyme at these temperatures. The student should feel comfortable performing these experiments in the lab and experiments that are related to what was learned in the lab today. Notes: Enzymes have Important Roles: - The international union of biochemistry and molecular biology recognizes six classes of enzymes. o 1. Oxidoreductases: Catalyze oxidation and reduction reactions. o 2. Transferases: Catalyze the transfer of a group from one molecule to a second. o 3. Hydrolases: Catalyze the breaking, or hydrolysis, of bonds.