bio chap 11 Flash Cards

 
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Apoptosis involves all but the following: lysis of the cell 0 kap08e Sun, 18 Oct 2009 18:38:47 GMT view revision history
Consider this pathway: epinephrine → G protein-coupled receptor → G protein → adenylyl cyclase → cAMP. Identify the second messenger. cAMP 0 kap08e Sun, 18 Oct 2009 18:38:47 GMT view revision history
Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because intracellular receptors are present only in target cells. 0 kap08e Sun, 18 Oct 2009 18:38:47 GMT view revision history
Protein phosphorylation is commonly involved with all of the following except activation of G protein-coupled receptors. 0 kap08e Sun, 18 Oct 2009 18:38:47 GMT view revision history
Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells? Glycogen breakdown was observed only when epinephrine was administered to intact cells. 0 kap08e Sun, 18 Oct 2009 18:33:02 GMT view revision history
The activation of receptor tyrosine kinases is characterized by dimerization and phosphorylation. 0 kap08e Sun, 18 Oct 2009 18:33:02 GMT view revision history
Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane? ligand-gated ion channel 0 kap08e Sun, 18 Oct 2009 18:33:02 GMT view revision history
Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because they amplify the original signal manyfold. 0 kap08e Sun, 18 Oct 2009 18:33:02 GMT view revision history
Apoptosis _____. is essential for normal development of the nervous system 0 kap08e Sun, 18 Oct 2009 18:17:01 GMT view revision history
Cells of the gastrointestinal (GI) tract and cells of the heart respond differently to epinephrine because _____. there are differences in the proteins found in the two types of cells 0 kap08e Sun, 18 Oct 2009 18:17:01 GMT view revision history
In liver cells, epinephrine stimulates the breakdown of glycogen. As the signal-transduction pathway progresses, _____. the signal is amplified 0 kap08e Sun, 18 Oct 2009 18:17:01 GMT view revision history
IP3 (inositol trisphosphate) acts by _____. opening Ca2+ channels 0 kap08e Sun, 18 Oct 2009 18:15:14 GMT view revision history
IP3 (inositol trisphosphate) is produced as a result of _____. the cleavage of a certain kind of phospholipid in the plasma membrane. 0 kap08e Sun, 18 Oct 2009 18:15:14 GMT view revision history
A difference between the mechanisms of cAMP and Ca2+ in signal transduction is that cAMP _____ and Ca2+ _____. is synthesized by an enzyme in response to a signal; is released from intracellular stores 0 kap08e Sun, 18 Oct 2009 18:15:14 GMT view revision history
In a typical cell, calcium ions _____. are often concentrated within the endoplasmic reticulum 0 kap08e Sun, 18 Oct 2009 18:15:14 GMT view revision history
cAMP usually directly activates _____. protein kinase A 0 kap08e Sun, 18 Oct 2009 18:09:12 GMT view revision history
Second messengers tend to be water-soluble and small. This accounts for their ability to _____. rapidly move throughout the cell by diffusion 0 kap08e Sun, 18 Oct 2009 18:09:12 GMT view revision history
The source of phosphate for a phosphorylation cascade is _____. ATP 0 kap08e Sun, 18 Oct 2009 18:09:12 GMT view revision history
Phosphorylation _____. can either activate or inactivate a protein 0 kap08e Sun, 18 Oct 2009 18:09:12 GMT view revision history
The general name for an enzyme that transfers phosphate groups from ATP to a protein is _____. ( protein kinase 0 kap08e Sun, 18 Oct 2009 18:06:17 GMT view revision history
The cellular response of a signal pathway that terminates at a transcription factor would be _____. the synthesis of mRNA 0 kap08e Sun, 18 Oct 2009 18:06:17 GMT view revision history
What event would activate a G protein? replacement of GDP with GTP 0 kap08e Sun, 18 Oct 2009 18:06:17 GMT view revision history
If a modified form of GTP that cannot be enzymatically converted to GDP were added to a culture of cells, the likely result would be _____. that the activated G proteins would remain locked in the "on" position, transmitting signal even in the absence of a signaling molecule 0 kap08e Sun, 18 Oct 2009 18:06:17 GMT view revision history
A G protein is active when _____. GTP is bound to it 0 kap08e Sun, 18 Oct 2009 18:01:26 GMT view revision history
The binding of a signal molecule to a ligand-gated ion channel _____. affects the membrane potential 0 kap08e Sun, 18 Oct 2009 18:01:26 GMT view revision history
Which of the following is activated when the binding of single molecules causes it to form a dimer? tyrosine-kinase receptors 0 kap08e Sun, 18 Oct 2009 18:01:26 GMT view revision history
G-protein-linked receptors _____, whereas receptor tyrosine kinases _____. are not enzymes; have enzymatic function 0 kap08e Sun, 18 Oct 2009 18:01:26 GMT view revision history
Testosterone and estrogen are lipid-soluble signal molecules that cross the plasma membrane by simple diffusion. If these molecules can enter all cells, why do only specific cells respond to their presence? Nontarget cells lack the intracellular receptors that, when activated by the signal molecule, can interact with genes in the cell's nucleus. 0 kap08e Sat, 17 Oct 2009 21:51:03 GMT view revision history
Steroid hormones can enter a cell by simple diffusion. Therefore steroids _____. do not initiate cell signaling by interacting with a receptor in the plasma membrane. 0 kap08e Sat, 17 Oct 2009 21:51:03 GMT view revision history
A small molecule that specifically binds to a larger molecule is called a(n) _____. ligand 0 kap08e Sat, 17 Oct 2009 21:51:03 GMT view revision history
Receptors for signal molecules _____. can be found as part of the plasma membrane or found within the cytoplasm 0 kap08e Sat, 17 Oct 2009 21:51:03 GMT view revision history
Testosterone does not affect all cells of the body because _____. not all cells have cytoplasmic receptors for testosterone 0 kap08e Sat, 17 Oct 2009 21:49:20 GMT view revision history
Cells use different signaling strategies to achieve different goals. In hormonal signaling _____. specialized cells release hormone molecules into the circulatory system, permitting distant cells to be affected 0 kap08e Sat, 17 Oct 2009 21:49:20 GMT view revision history
Certain yeast cells secrete a molecule called the α factor. The purpose of this molecule is to _____. stimulate an a yeast cell to grow toward the α cell 0 kap08e Sat, 17 Oct 2009 21:49:20 GMT view revision history
When a platelet contacts a damaged blood vessel, it is stimulated to release thromboxane A2. Thromboxane A2 in turn stimulates vascular spasm and attracts additional platelets to the injured site. In this example thromboxane A2 is acting as a _____. local regulator 0 kap08e Sat, 17 Oct 2009 21:49:20 GMT view revision history

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