Excess intracellular iron is toxic to cells (iron-induced toxicity). Ferritin is an intracellular iron storage protein that binds excess iron. The presence of ferritin can protect cells from iron-induced toxicity. Show In an experiment to investigate the effects of dietary iron intake on ferritin synthesis, rats were given food containing different amounts of iron. Subsequently, the levels of ferritin protein in the liver were measured. The results are shown in Figure 1. Based on these and other data, researchers have developed the following model demonstrating how ferritin synthesis is regulated by iron. When iron levels are low, a repressor of translation, iron response protein (IRP), binds to an iron response element (IRE), which is a stem-loop structure near the 5¢ end of ferritin mRNA. When iron levels are high, intracellular iron binds to the IRP, and the iron-IRP complex dissociates from the IRE, permitting ribosomes to proceed with the translation of ferritin mRNA. Figure 2 represents the model of the regulation of ferritin mRNA translation by iron. Figure 2. Model of regulation of ferritin synthesis by iron Based on the model of ferritin synthesis presented in Figure 2, which of the following describes the role of feedback on the control of intracellular iron levels? What is the role that epinephrine plays in this pathway?Epinephrine is an important cell signaling molecule in the fight or flight response. Also known as adrenaline, epinephrine is an efficient messenger that signals many cell types throughout the body with many effects. In the lungs, epinephrine binds to receptors on smooth muscle cells wrapped around the bronchioles.
What best describes the epinephrine signaling pathway?Based on Figure 1, which of the following statements best describes the epinephrine signaling pathway? In involves enzymes activating other enzymes. Which of the following statements best describes the role of adenylyl cyclase in the epinephrine signaling pathway? It accelerates the production of a second messenger.
What does the signaling pathway triggered by epinephrine cause to occur in liver cells?What does the signaling pathway triggered by epinephrine cause to occur in liver cells? Binding of epinephrine leads to increase in metabolic rate.
What are the signal amplification steps in the epinephrine signaling pathway?Terms in this set (11). Reception (1) Ligand (Epinephrine) attaches to G-protein (receptor) within the plasma membrane of the target liver cell.. Reception (2) ... . Reception (3) ... . Transduction (4) ... . Transduction (5) ... . Transduction (6) ... . Transduction (7) ... . Transduction (8). |
The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells
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