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20 Cards in this Set
- Front
- Back
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Signal Transduction |
Signaling molecule binds to receptor Relay molecule activated Series phosphorylation by inactive protein kinases (ATP ---> ADP) Last one releases cellular response |
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PP |
Protein phosphatases take phosphate from active kinases and make them inactive
Reverses signal transduction |
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How signal is transmitted in many pathways |
By a cascade of protein phosphorylations |
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Protein kinases |
Transfer phosphates from ATP to protein (phosphorylation) |
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Protein phosphatases |
Remove phosphates from proteins (dephosphorylation) |
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Second messengers |
Nonprotein, water-soluble molecules or ions |
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Functions of second messengers |
Can spread throughout a cell by diffusion
Participate in pathways initiated by GPCRs and RTKs |
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Most common second messengers |
cAMP (cyclic AMP) Calcium |
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Example of cAMP |
Adenylyl cyclase converts ATP to cAMP in response to a signal
Protein kinase A (PKA) then activates and phosphorylates proteins |
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How to fine tune a response |
Amplify the signal Specificity Scaffolding proteins Signal termination |
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Amplify the signal |
And thus the response
A small number of molecules binding to their receptors activate many pathway components
Molecule initiates cascade Cascade splits to two responses |
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Specificity |
Different cell types have different proteins that respond to signals |
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Scaffolding proteins |
Relay proteins
Increase signal transduction efficiency by grouping different proteins involved in the same pathway |
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Signal termination |
Reversibility
Unbound receptors are inactive grouping of kinases. Speeds up set of reactions |
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Apoptosis |
Programmed cell death
Involves activation of signal transduction pathways |
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What happens to organelles and DNA during apoptosis |
Organelles and DNA are fragmented and packaged into vesicles Digested by macrophages |
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Macrophages during apoptosis |
Caspases DNases |
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Caspases |
Break down parts of the cell, mostly proteins |
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DNases |
Break down DNA |
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Apoptosis during hand/paw development |
Cells in interdigital tissue undergo apoptosis to form a space between digits |
