front 1 From the perspective of the cell receiving the message, the three stages of cell signaling are: | back 1 signal reception, signal transduction, and cellular response |
front 2 The process of transduction usually begin | back 2 when the signal molecule changes the receptor protein in some way |
front 3 The signal transduction pathway in animal cells that uses epinephrine | back 3 activates the breakdown of glycogen in liver and skeletal muscles |
front 4 A small molecule that specifically binds to another molecule, usually a larger one | back 4 is called a ligand |
front 5 Which is (are) true of ligand-gated ion channels? | back 5 A. they are important in the nervous system B.they lead to changes in sodium and calcium concentrations in the cell C. they open or close in response to a chemical signal |
front 6 a receptor protein in a membrane that recognizes a chemical signal is most similar to | back 6 the active site of an enzyme in the cytoplasm that binds to a specific substrate |
front 7 Most signaling molecules | back 7 A. bind to specific sites on receptor proteins in a membrane B. are water-soluble |
front 8 what would be TRUE for the signaling system in an animal cell that lacks the ability to produce GTP | back 8 It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane |
front 9 Membrane receptors that attach phosphates to specific amino acids in proteins are | back 9 called receptor tyrosine-kinases |
front 10 Which are chemical messengers that pass through the plasma membrane of the cells and have receptor molecules in the cytoplasm | back 10 B. nitric acid C. testosterone |
front 11 Testosterone functions inside a cell by | back 11 binding with a receptor protein that enters the nucleus and activates specific genes |
front 12 The receptors for a group of signaling molecules known as growth factors are often | back 12 receptor tyrosine kinases |
front 13 In general, a signal transmitted via phosphorylation of a series of proteins | back 13 brings a conformational change to each Protein |
front 14 Which is (are) TRUE regarding the activity of a protein regulated by phosphorylation | back 14 It depends on the balance in the cell between active kinase and active phosphatase molecules |
front 15 Which is (are) widely used and second messenger in signal transduction pathways | back 15 A. calcium ions B. cyclic AMP C. inositol triphosphate |
front 16 An animal deficient in adenylyl cyclase | back 16 would not respond properly to epinephrine |
front 17 the general name for an enzyme that transfers phosphate groups from ATP to a protein is | back 17 protein kinase |
front 18 the toxin of Vibrio Cholerae causes profuse diarrhea because it | back 18 modifies a G protein involved in regulating salt and water secretion |
front 19 In a typical cell, calcium ions are | back 19 A. far more abundant in the blood and other extracellular fluid than in the cytoplasm B. rapidly released from the endoplasmic reticulum in response to G-protein mediated signals C. often concentrated within the endoplasmic reticulum |
front 20 Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins | back 20 receptor tyrosine kinase activity |
front 21 Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed | back 21 cAMP |
front 22 An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum | back 22 phospholipase C |
front 23 A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following | back 23 a decrease in transcriptional activity of certain genes |
front 24 The response of a particular cell to a signal depends on | back 24 A. its particular collection of signal receptor proteins B. its relay proteins C. the proteins needed to carry out the response |
front 25 Which example below is a protein that can hold several other relay proteins as it binds to an activated membrane receptor | back 25 scaffolding protein |