Term
| Earl W. Sutherland studied mechanisms behind the hormone, _______________. |
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Definition
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Term
| The three basic steps of cell communication |
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Definition
- Reception
- Transduction
- Cellular Response
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Term
| Which of the three basic steps of cell communication is the longest? |
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Definition
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Term
| What happens during reception (generally)? |
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Definition
| A ligand binds to a receptor associated with the target cell; signaling molecule is received by target cell |
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Term
| What happens during transduction (generally)? |
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Definition
| Molecules are relayed in the signal transduction pathway; the molecules are relaying the "message" that needs to be communicated to the cell. |
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Term
| What happens during the Cellular Response (generally)? |
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Definition
There isn't much to explain here, but here are some examples of cellular responses:
- Movement
- Transport
- Death
- Division
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Term
| Which receptor(s) did we learn about that show up in the plasma membrane? |
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Definition
- G Protein-Coupled Receptor (GPCR)
- Receptor Tyrosine Kinase (RTK)
- Ligand-gated ion channel receptor (Sorry, no acronym lol)
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Term
| What do receptors in the plasma membrane do? |
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Definition
| They bind to a hydrophilic ligands (if the ligand were hydrophobic, it would be able to pass through the membrane); Since the ligand can't enter the cell, it uses the receptor to transmit a signal. |
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Term
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Definition
- Signal binds GPCR to activate receptor
- G-protein moves along membrane to bind GPCR
- Inactive state: G-protein + GDP
- Active state: G-protein + GTP (this displaces the GDP)
- G-protein activates enzyme
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Term
| GPCR (Inactivation/Resetting) |
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Definition
- Signal leaves receptor
- G-protein leaves enzyme
- G-protein has GTPase activity (an inorganic phosphate is hydrolyzed off of GDP to make GDP
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Term
| Kinase is another way of saying __________________. |
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Definition
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Term
| Receptor Tyrosine Kinase (RTK) (Activation) |
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Definition
- 2 signals bind to respective RTKs
- 2 RTKs binds to form a dimer
- RTKs have kinase activity
- They autophosphorylate tyrosines on intracellular side
- Multiple relay molecules bind RTK
- Two signals; multiple cellular responses
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Term
| Receptor Tyrosine Kinase (RTK) (Inactivation/Resetting) |
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Definition
- Relay proteins are inactivated (they leave RTK)
- Phosphates are removed from tyrosines on RTK
- RTK dimer separates
- Signals leave RTK
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Term
| Ligand-gated ion channel receptor (Activation) |
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Definition
- Essentially like a "key" to a gate that ions can pass through (bearing in mind that charged particles cannot enter the membrane otherwise)
- Ions diffuse through channel into cell
- Ions lead to cellular respone(s)
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Term
| Ligand-gated ion channel receptor (Inactivation/Resetting) |
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Definition
- Voltage difference across membrane (membrane potential) detected by cell
- Ligand leaves receptor
- Gate closes
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Term
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Definition
- Binds small, hydrophobic (non-polar) ligand that can permeate the membrane
- Ligand/signal permeates membrane and binds intracellular receptor forming a complex (this is the active state)
- Comples enters nucleus and binds DNA, serving as a transcription factor
- This ultimately leads to cellular response
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Term
| Events That Occur in Transduction |
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Definition
- Phosphorylation Cascades
- Second Messengers
- Amplification
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Term
| Phosphorylation Cascade (Mainly Proteins) (Activation) |
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Definition
- Kinases are involved (activation)
- One molecule in the process activates the other until the last molecule involved in response is activated (it's like a domino effect type thing)
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Term
| Phosphorylation Cascade (Inactivation/Resetting) |
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Definition
- Molecules change shape once message is relayed OR phosphates are removed off of each molecule by a specific phosphatase (PP)
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