GTP is an important high-energy molecule that facilitates the activation of many cellular sig- nal transduction pathways. Certain genetic dysfunctions can inhibit the ability of a cell to synthesize GTP. Which of the following describes the most direct result of GTP synthesis inhibition? A B C D The cell would be able to carry out reception and transduction but would not be able to produce the cellular response in the relevant signal transduction pathway. The G protein-coupled receptor will not be able to bind corresponding ligands, inhibiting the reception components of the relevant signal transduction pathway. The cell will use ATP instead of GTP to activate the G protein on the intracellular region of the G protein-coupled receptor. The cell would not be able to activate G proteins on the intracellular regions of G pro- tein-coupled receptors.

GTP is an important high-energy molecule that facilitates the activation of many cellular sig- nal transduction pathways. Certain genetic dysfunctions can inhibit the ability of a cell to synthesize GTP. Which of the following describes the most direct result of GTP synthesis inhibition? A B C D The cell would be able to carry out reception and transduction but would not be able to produce the cellular response in the relevant signal transduction pathway. The G protein-coupled receptor will not be able to bind corresponding ligands, inhibiting the reception components of the relevant signal transduction pathway. The cell will use ATP instead of GTP to activate the G protein on the intracellular region of the G protein-coupled receptor. The cell would not be able to activate G proteins on the intracellular regions of G pro- tein-coupled receptors.

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter9: Cell Communication

Section: Chapter Questions

Problem 1VCQ: Figure 9.8 HER2 is a receptor tyrosine kinase. In 30 percent of human breast cancers, HER2 is...

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The G protein coupled receptor (GPCR) pathway elicits diverse intracellular responses in different cells. The basic steps of GPCR signaling are outlined in this diagram. Which of the following statements correctly describes the process of GPCR signaling? The GPCR activation is reversible after the signal of the ligand diminishes. The membrane-embedded enzyme uses GTP as a secondary messenger to initiate gene expression. The ligand attaches to both the GPCR and the membrane-embedded enzyme to activate the GPCR pathway. The ligand-bound GPCR sends a GTP molecule to an enzyme in the membrane and switches it into an active state.
GTP binding proteins are molecular switches. How do GTP binding proteins work? Provide two examples of GTP binding proteins that function in intracellular protein transport. Make a drawing that illustrates the function of each of these proteins in their respective roles. Predict the direct outcome of a mutation that: Inhibits GTPase activity Inhibits interaction with the GEF
Many cellular processes require the hydrolysis of GTP to GDP. However, unlike ATP, GTP hydrolysis is often not used as an energy source for the cell, but rather, is associated with a group of enzymes called GTPases. Which of the following statements about GTP and GTPases is correct? 1. GTPase activating protein (GAP) binds to GTPase when it is in the active state. 2. The exchange factor GEF binds GTP directly and delivers it to the GTPase. 3. The "switching" behaviour of GTPase is because GTP hydrolysis causes the enzyme to change shape. 4. Structural differences in the terminal phosphate group explains why ATP hydrolysis releases energy and GTP does not. O 1,2 and 3 O 1 and 3 O 2 and 4 O 4 only O All of 1,2.3 and 4 are correct
In the case of GPCR (G protein coupled receptor) signaling pathways, which of the following statements is INCORRECT? The gamma subunit of the trimeric G protein has a transmembrane domain whereas the alpha and beta subunits are peripheral proteins If G alpha was locked in a GTP bound state, it would be bound to the effector enzyme rather than to the beta and gamma subunits. In some but not all signaling pathways, when the beta and gamma subunits are separated from alpha - the beta/gamma pair can also stimulate the activation of effectors
Researchers have found that a certain signal transduction pathway, illustrated in the figure below, may be responsible for the development of cancer in pancreatic cells. In normal pancreatic cells, where the pathway remains inactive, a membrane-bound receptor called Ptc inhibits a downstream protein known as Smo. The inhibition of Smo blocks the activa- tion of a complex of proteins known as the HSC, which results in the cleaving of one of its proteins called Ci. The cleaving of Ci, in turn, prevents the pathway from initiating the syn- thesis of division-facilitating enzymes. A Ptc B Smo с inhibition D A model of a Ptc signal transduction pathway under normal conditions. HSC Ci cleavage A certain protein called the Hedgehog protein (Hh) is found to activate this signal transduction pathway and trigger uninterruptable cell division. cell division not initiated Which of the following describes the most plausible mechanism by which Hh triggers uninterruptable cell division? Hh binds to…
Signaling activity of G proteins is controlled by GTPase activating proteins (GAPs) and Guanine exchange factors (GEFs). What are the mechanisms by which GAPS and GEFs control G protein functions? GEFS inhibit G protein functions by stimulating GTP hydrolysis; GAPs activate G protein functions by stimulating GDP-GTP exchange. O GAPS inhibit G protein functions by stimulating GTP hydrolysis; GEFs activate G protein functions by stimulating GDP-GTP exchange. GEFS inhibit G protein functions by stimulating GTP hydrolysis; GAPS activate G protein functions by inhibiting GDP-GTP exchange. GAPs stimulate G protein functions by blocking GTP hydrolysis; GEFS inhibit G protein functions by stimulating GTP-GDP exchange. GAPS inhibit G protein functions by stimulating GDP-GTP exchange; GEFS activate G protein functions by stimulating GTP hydrolysis
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G protein coupled receptors play an important role in signal transduction in many cells. Label the four essential components of the G protein coupled receptor signaling system (blanks a-d in the picture) by choosing from the menus below. a b b Each answer will be used at most once, while some will not be used at all (select one for each): Group of answer choices transcription factor с transcription factor Show Transcribed Text d transcription factor B C. transcription factor G protein second messenger G protein second messenger IE G protein second messenger G protein second messenger receptor receptor receptor receptor enzyme enzyme enzyme enzyme steroid hormone steroid hormone steroid hormone steroid hormone
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What is the main benefit of cell signaling via direct physical contact and cell signaling over short distqnces (ex.: nerve cell signaling)?