Flashcards on Hormone Receptor Pathways and Signaling
Hormone Receptor Pathways and Signaling Explained
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Cell Signaling and Hormones
10 cards
Card 1
Question: According to the text, what does oxytocin do in myoepithelial cells, and what mechanism does it use to achieve this?
Answer: It activates a pathway that increases intracellular calcium, which can trigger contraction (via troponin or calmodulin and kinases) and thus initiate
Card 2
Question: Besides muscle contraction, what other functions can an increase in intracellular Ca2+ influence?
Answer: It can phosphorylate various proteins, affect membrane permeability, metabolism, cell proliferation, and protein synthesis.
Card 3
Question: Where are steroid hormone receptors located, and why are they found there?
Answer: Steroid receptors are intracellular—found in the cytosol or directly in the nucleus—because steroid hormones can diffuse across the lipid bilayer of t
Card 4
Question: What are steroid receptors typically bound to when they are in an inactive state?
Answer: Heat shock proteins (HSPs), which dissociate when a hormone binds.
Card 5
Question: What happens when a steroid hormone (e.g., testosterone) crosses the cell membrane and binds to an intracellular receptor?
Answer: The hormone causes the heat shock proteins to dissociate, activating the receptor. The activated receptor then binds to a specific gene sequence (horm
Card 6
Question: What does the acronym HRE stand for, and what is its function?
Answer: HRE stands for hormone response element. It is a specific gene sequence to which the activated hormone-receptor complex binds, influencing gene expres
Card 7
Question: What biological effects can result from gene activation when the steroid receptor complex binds to an HRE?
Answer: It can stimulate mitosis (cell division), DNA replication, transcription, and translation, leading to the synthesis of various proteins. These protein
Card 8
Question: According to the text, why do some peptide hormones require extracellular membrane receptors?
Answer: Because peptide hormones cannot diffuse across the lipid bilayer of the cell membrane, they must act via receptors located on the cell surface.
Card 9
Question: How is a continuously rising level of cAMP in a cell stopped or dampened?
Answer: By the enzyme phosphodiesterase (PDE), which breaks down cAMP, thereby terminating or dampening the signaling pathway.
Card 10
Question: What does the acronym PDE stand for, and what is its function in signaling?
Answer: PDE stands for phosphodiesterase. It degrades cAMP (and can also affect other signaling molecules), thereby stopping or reducing the progression of si