Concept explainers
Effect of BPA on Insulin Secretion Bisphenol A (BPA) is an endocrine disruptor that may increase the risk of type 2 diabetes. Angel Nadal suspected that BPA disrupts insulin
FIGURE 34.11 Effects of BPA and DPN on glucose-stimulated insulin secretion. DPN is a chemical known to bind and activate estrogen receptors on pancreatic cells. A glucose concentration of 8 millimolar (mM) is equivalent to that of the blood after a meal.
How were the effects or DPN and BPA similar? How did they differ?
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Chapter 34 Solutions
Biology: The Unity and Diversity of Life (MindTap Course List)
- Diabetes often results in the production of reduced levels of insulin. Researchers claim that a drug that binds to and blocks the active site of GSK3 might mimic the role of insulin in the pathway shown in Figure 2. Provide reasoning to justify the researchers' claim.arrow_forwardIn some forms of diabetes, a mutation in the b subunit of the insulin receptor abolishes the enzymatic activity of that subunit. How does the mutation affect the cell’s response to insulin? Can additional insulin (e.g., from injections) overcome the defect?arrow_forwardOverexpression of this receptor in the cells of the adrenal gland causes Cushing's syndrome, a disease caused by the overproduction of cortisol. One strategy that scientists have employed to treat this disease is the use of small molecules that bind to, but do not activate, MC2R. This type of molecule is generically referred to as an antagonist. How can an antagonist bind to the same receptor as ACTH but not activate it? O a. The antagonist can bind covalently while ACTH binds non-covalently O b. The antagonist is only partially complimentary to the binding pocket of MC2R O The antagonist binds to ACTH and blocks it from binding to the receptor properly O d. The antagonist is the exact same structure as ACTH but since it is synthetic it doesn't work One cause of Cushing's syndrome is the inappropriate production of GPCRS in the adrenal gland that are not normally present in those cells. When these receptors are activated they result in the production of cortisol. Which statement about…arrow_forward
- In muscle cells, when adrenaline binds to beta-adrenergic receptor, it trigger signaling cascade leading to active glycogen phosphorylate breaks up glycogen into glucose subunits (Glycogen -> G1P). Base on following figure, describe this signaling cascade:arrow_forwardHuman growth hormone binds to a cell-surface membrane protein that is not a receptor tyrosine kinase. The intracellular domain of the receptor can bind other proteins inside the cell. Furthermore, studies indicate that the receptor is monomeric in the absence of hormone but dimerizes on hormone binding. Propose a possible mechanism for growth-hormone signaling.arrow_forwardThe physiological effects of epinephrine should in principle be mimicked by addition of cAMP to the target cells. In practice, addition of cAMP to intact target cells elicits only a minimal physiological response. Why? When the structurally related derivative dibutyryl cAMP (shown below) is added to intact cells, the expected physiological response is readily apparent. Explain the basis for the difference in cellular response to these two substances. Dibutyryl cAMP is widely used in studies of cAMP function.arrow_forward
- Suppose that you had a monoclonal antibody that recognized phosphotyros- ine. How would you expect that antibody to affect insulin signaling?arrow_forwardNovolog differs from "normal" insulin in that: Select one: a. An aspartic acid has been substituted for proline at B28 b. The proline at B28 and the lysine at B29 have been reversed c. A glycine has been substituten in at A21, and two new arginines have been added as B31 and B32 d. A "C-peptide" chain has been added e. The usual insulin molecule has been combined with zinc isophanearrow_forwardHbA1c is used to monitor blood glucose levels because hemoglobin is the only protein in blood that is covalently modified by glucose. True False Insulin Glargine is a long-acting form of insulin that is synthesized with several D-amino acids that slow its proteolytic degradation and extend the half-life of the insulin Glargine molecule. True Falsearrow_forward
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- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning