
Biochemistry
9th Edition
ISBN: 9781319114671
Author: Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher: W. H. Freeman
expand_more
expand_more
format_list_bulleted
Question
What is the substrate of salivary amylase in both experiments?

Transcribed Image Text:Part 1. Effect of pH
The pH of an enzyme's environment can affect its activity by interfering with the charge on its
amino acids. Small changes in pH can result in enzyme denaturation and subsequent loss of catalytic
activity. Each enzyme has a characteristic optimum pH which usually falls within the physiological pH
range. Note that for the purpose of this experiment, distilled water has a pH of -7.00.
Watch this video and answer the related questions in the questions section of this activity.
The experiment in the video follows this procedure:
1. Prepare a water bath maintained at 37 C.
2. Mix the components shown in the table below:
Test Tube
1% Starch
0.2M NaCI
Acid/ Basel Water
Salivary
Solution
Amylase
A
10 ml
0.5 mL
1 ml 0.05 M HCI
2 ml
10 mL
0.5 mL
1 mL distilled water
2 mL
10 mL
0.5 ml
1 mL 0.05M NaOH
2 ml
3. Place the test tubes in a water bath.
4. Prepare a spot plate that contains two drops of I, in KI.
5. When the temperature of the test tube contents is 37°C, remove a few drops from the test
tubes and place them in the corresponding spot plates.
6. Withdraw another two drops every two minutes until a spot shows no color change.
Part 2. Effect of Temperature
As the temperature of an enzymatically catalyzed reaction increases, so does the speed of the
reaction. However, when the temperature goes beyond a certain point, it causes adverse effects on
the enzyme's tertiary structure. As a result, enzyme activity siows down. The temperature that allows
peak enzyme activity is known as the optimum temperature for that enzyme.
Watch this video and answer the related questions in the questions section of this activity.
The experiment in the video foilows this procedure:
1. Based on the results from part 1, choose the mixture that showed high amylase activity.
2. Mix the components of this mixture in a different test tube except for the salivary amylase
which should be placed in a separate, smaller test tube.
3. Let the two test tubes equilibrate in a water bath maintained at 4°C for 10 minutes.
4. After 10 minutes, mix the sailivary amylase with the other components.
5. Prepare a spot plate with 9 of its wells containing two drops of I, in Kl each.
6. Remove a few drops from the test tubes and place them in the corresponding spot plate.
7. Withdraw another two drops every two minutes until all wells with I, in KI are filled.
Repeat the same process but at 37°C and in 70°C.
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution
Trending nowThis is a popular solution!
Step by stepSolved in 3 steps

Knowledge Booster
Similar questions
- The Beutler test is used to diagnose GALT (UDP-glucose uridyltransferase) deficiency in infants. Blood from the heel is spotted onto filter paper and the spot is then subjected to an enzyme assay. Galactose 1-phosphate, NADP+ and UDP-glucose are added as substrates to the dried blood. The increase in absorbance at 340nm is measured over time which corresponds to reduction of NADP+ to NADPH . The amount of GALT activity in the blood of patients is therefore measured by stoichiometric relationship to the amount of NADPH produced from NADP+. However, GALT does not directly reduce NADP+ as you can see in the above diagram. Instead, the glucose 1-phosphate product from this reaction is shuttled into the oxidative phase of the pentose phosphate pathway by enzymes also present in RBCs. Which three (or possibly more if you must) enzymes downstream of GALT allow for quantitative correlation of a product of GALT with the appearance of NADPH? What is the stoichiometric relationship…arrow_forwardIs liver catalase active within a narrow or broad ph range?arrow_forwardThe enzymatic activity of PFK1 is generally measured by set- ting up a coupled enzyme assay system whereby aldolase, triose phos- phate isomerase, and glycerol-3-phosphate dehydrogenase are added to the assay mixture. For the latter enzyme, NADH is added and its change in concentration is readily monitored at 340 nm. Write the chain of reactions catalyzed by these enzymes using structural formulas, label substrates and products, and explain why the coupled en- zyme assay system leads to oxidation of NADH. While the chain of reac- tions is similar to those in glycolysis, there is a critical difference because of the dehydrogenase enzyme. Describe how this enzyme causes the chain of reactions to differ from those in glycolysis.arrow_forward
- Describe experimental enzyme inhibition and how it leads to a deeper understanding of enzyme mechanisms. Explain mechanism-based enzyme inhibition. Describe enzyme inhibition by a transition-state analog. For fluoroacetate and hypoglcyin A, explain how each of these mechanism-based inhibitors is converted to the actual enzyme inhibitor and how this inhibitor then inhibits the relevant enzyme..arrow_forwardBriefly explain how ester hydrolysis experiments helped to provide evidence for the mechanism of peptide hydrolysis catalyzed by chymotrypsin.arrow_forward2-Bromopalmitoyl-CoA inhibits the oxidation of palmitoyl-CoA by isolatedmitochondria but has no effect on the oxidation of palmitoylcarnitine. What is the most likely site of inhibition by 2-bromopalmitoyl-CoA?arrow_forward
- The natural enzyme is recreated by mixing isolated regulatory and catalytic subunits of ATCase. What biological relevance does this observation have?arrow_forwardNeuraminidase (NA) catalyzes a hydrolysis of the glycosidic linkages of sialic acids using a mechanism shown in Fig. (a). and Fig. (b) shows competitive inhibitors of NA Considering the mechanism of NA, why do zanamivir and oseltamivir inhibit NA so potently?arrow_forwardWhat ion or ions are required for PYC activity? What ion or ions inhibit PYC activity? Remember, Mg2+ is the control substance, and not expected to have any effect on the enzyme’s activity.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- BiochemistryBiochemistryISBN:9781319114671Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.Publisher:W. H. FreemanLehninger Principles of BiochemistryBiochemistryISBN:9781464126116Author:David L. Nelson, Michael M. CoxPublisher:W. H. FreemanFundamentals of Biochemistry: Life at the Molecul...BiochemistryISBN:9781118918401Author:Donald Voet, Judith G. Voet, Charlotte W. PrattPublisher:WILEY
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage LearningBiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningFundamentals of General, Organic, and Biological ...BiochemistryISBN:9780134015187Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. PetersonPublisher:PEARSON

Biochemistry
Biochemistry
ISBN:9781319114671
Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher:W. H. Freeman

Lehninger Principles of Biochemistry
Biochemistry
ISBN:9781464126116
Author:David L. Nelson, Michael M. Cox
Publisher:W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul...
Biochemistry
ISBN:9781118918401
Author:Donald Voet, Judith G. Voet, Charlotte W. Pratt
Publisher:WILEY

Biochemistry
Biochemistry
ISBN:9781305961135
Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal
Publisher:Cengage Learning

Biochemistry
Biochemistry
ISBN:9781305577206
Author:Reginald H. Garrett, Charles M. Grisham
Publisher:Cengage Learning

Fundamentals of General, Organic, and Biological ...
Biochemistry
ISBN:9780134015187
Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. Peterson
Publisher:PEARSON