Term
| 5 distinctive characteristics of ion channels |
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Definition
1. ion channels are formed from glycoproteins that transverse the cell membrane
2. they are formed by aggregation of subunits, each a protein by itself, into a cylindrical configuration that allows pore, thus forming a kind of tube
3. ions cross through their channels by electrical potential or concentration differences across the cell membrane
4. these channels are selective for the types of ions they allow to cross
5. the variety & number of ion channels a cell has will vary by its type |
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Term
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Definition
| low-weight diffusible molecules that are used in signal transduction to relay a signal within a cell |
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Term
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Definition
| any process by which a cell converts one kind of signal or stimulus into another |
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Term
| 3 basic types of second messenger molecules |
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Definition
1. hydrophobic molecules
2. hydrophilic molecules
3. gases |
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Term
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Definition
1. cAMP
2. cGMP
3. Ca2+
4. IP3
5. DAG |
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Term
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Definition
| molecules that are released from the postsynaptic site & diffuse "backwards" to affect the presynaptic terminal |
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Term
| 3 main retrograde signals |
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Definition
1. NO
2. CO
3. AA & metabolites of AA |
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Term
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Definition
| serve to amplify a signal |
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Term
| 3 ways that second messenger mediated events are different from directly-gated events |
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Definition
1. can close channels
2. time course is much longer
3. directly gated channels are not affected by voltage & thus do not contribute to AP |
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Term
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Definition
| a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific target molecules |
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Term
| The largest group of kinases is that of ______, which act on & modify the activity of specific proteins |
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Definition
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Term
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Definition
| modify other proteins by chemically adding phosphate groups to them |
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Term
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Definition
1. catalytic domain
2. regulatory domain |
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Term
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Definition
| enzymes that remove phosphate groups that have been attached to amino acid residues of proteins by protein kinases |
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Term
| 3 general classes of signal transduction receptors |
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Definition
1. receptors that penetrate the plasma membrane & have intrinsic enzymatic activity
2. receptors that are coupled, inside the cell, to GTP-binding & hydrolyzing proteins
3. receptors that are found intracellularly & upon ligand-binding migrate to the nucleus where the ligand-receptor complex directly affects gene transcription |
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Term
| GCPRs are termed ______ receptors |
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Definition
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Term
| Why are "nuclear receptors" named as such? |
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Definition
| this class of receptors is intracellular & functions in the nucleus as transcription factors |
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Term
| Many enzymes are regulated by the covalent attachment of a ______, in ester linkage, to the side-chain hydroxyl group of a particular amino acid residue |
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Definition
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Term
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Definition
| transfers the terminal phosphate of ATP to a hydroxyl group on a protein |
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Term
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Definition
| catalyzes removal of the phosphate by hydrolysis |
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Term
| ______ may directly alter the effects of an enzyme, e.g. via a conformational change |
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Definition
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Term
| Altered enzyme activity may result from ______ that specifically recognizes the phosphorylated domain |
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Definition
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Term
| _______ is activated by cyclic-AMP (cAMP) |
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Definition
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Term
| reaction catalyzed by adenylate cyclase |
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Definition
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Term
| Binding of certain ______ to the outer surface of the cell activates adenylate cyclase to form cAMP within the cell |
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Definition
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Term
| Is cyclic AMP considered to be a second or primary messenger? |
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Definition
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