JBT Task 4 (0515)
Competency 208.5.4: Enzymology and Catalytic Mechanism – The graduate constructs models of enzymes, demonstrates how enzymes act as a catalyst in a reaction and factors that influence this reaction, and solves enzyme and catalysis problems.
Competency 208.5.5: Carbohydrate Metabolism, Adenosine Triphosphate (ATP) – The graduate constructs models of carbohydrates and demonstrates metabolism of carbohydrates; demonstrates how adenosine triphosphate (ATP) is essential to energy transfer in the cell and how irregularities in ATP synthesis in the cell can cause cytopathologies.
Task 4: Metabolism
More and more researchers are discovering that many diseases are caused by biochemical deficiencies or defects. That is, instead of indicating that a disease is caused by a nutritional deficiency, researchers recognize that an underlying cause may be a single molecular structure within a cell that fails to turn a cellular process on or off. This is particularly true regarding metabolism. For this task, you will consider the biochemical implications in a metabolic disorder involving a normal component of food—fructose.
You should compile your work for this task in a single document (e.g., Microsoft Word, Google Document) that includes diagrams, text explanations, and references. If a requirement asks for an explanation, you should provide a written response in a narrative style (i.e., complete sentences rather than bullet points).
Note: Multimedia presentations (e.g., PowerPoint, Keynote) will not be accepted due to potential originality concerns.
Note: Please save submission documents as *.doc, *.docx, *.rtf, or *.pdf files. If you are using Google Documents, you must save the file in *.pdf format and upload the *.pdf file.
A. Demonstrate your understanding of the biochemical basis of hereditary fructose intolerance (HFI) by doing the following:
1. Describe two important features that make all enzymes catalysts.
2. Create an original diagram, or series of diagrams, with clear labels, that demonstrates the entire enzymatic cycle described by the lock and key model OR the induced fit model.
3. Create an original diagram, or series of diagrams, with clear labels, that illustrates the activation energy of a reaction in the presence and absence of an enzyme.
4. Explain the reactions catalyzed by enzymes in the first two steps of fructose metabolism in the liver, including each of the following:
● the substrates acted on
● the enzyme catalysts
● the products generated
5. Discuss how a deficiency in aldolase B is responsible for HFI by doing the following:
a. Explain how the amount of the substrate of aldolase B is impacted by the deficiency.
b. Explain the role of the substrate in producing one condition of HFI (e.g., hypoglycemia, liver failure).
B. Explore how mitochondrial disease can occur at multiple levels in different mitochondrial processes by doing the following:
1. Explain what would hypothetically happen to the amount of ATP available to a cell if the entire Cori cycle were to occur and remain within a single cell (e.g., a muscle cell).
a. Identify specific numbers of ATP generated and used in the different parts of the cycle, in conjunction with your response from part B1.
2. Create an original dynamic diagram that shows how the citric acid cycle (CAC) is central to aerobic metabolism.
Note: A dynamic diagram is a clearly labeled diagram that uses arrows to indicate movement and interactions.
3. Explain where in the CAC a hypothetical defect of an enzyme could occur that would decrease the overall ATP production of the mitochondria, including each of the following:
● whether the entire cycle will continue to function
● what will happen to the cycle products
● why ATP production decreases
Note: This is a hypothetical defect, so the explanation should not include descriptions of any known disease.
4. Explain how a proton gradient is formed and used to make ATP during aerobic metabolism.
Note: The inclusion of a discussion of the electron transport chain and oxidative phosphorylation, including the role of oxygen, aids in the explanation of this process.
C. When you use sources, include all in-text citations and references in APA format.
Note: For definitions of terms commonly used in the rubric, see the Rubric Terms web link included in the Evaluation Procedures section.
Note: When using sources to support ideas and elements in an assessment, the submission MUST include APA formatted in-text citations with a corresponding reference list for any direct quotes or paraphrasing. It is not necessary to list sources that were consulted if they have not been quoted or paraphrased in the text of the assessment.
Note: No more than a combined total of 30% of a submission can be directly quoted or closely paraphrased from sources, even if cited correctly. For tips on using APA style, please refer to the APA Handout web link included in the General Instructions section.