Term
| What does cell communication underlie? |
|
Definition
| life cycle of entire organism |
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Term
| What are the two types of direct contact in a cell |
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Definition
cell junction (cells touching)
cell-cell recognition (use a receptor to touch cell nearby) |
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Term
| Describe cell communtication without contact (3) |
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Definition
Cell releases signaling
molecule that is then
detected by receptors
on target cell
Autocrine – cell
signaling itself
Paracrine/Synaptic –
nearby cells
Endocrine – action at a distance,
via circulation |
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Term
|
Definition
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Term
| What is paracrine/synaptic? |
|
Definition
|
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Term
|
Definition
| action at a distance, via circulation |
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Term
| What are the three stages of signaling pathways? |
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Definition
◦ Reception
◦ Signal transduction
◦ Response |
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Term
| What is reception in signaling pathways? |
|
Definition
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Term
| What is signal transduction in signaling pathways? |
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Definition
| Relay molecules in a signal transduction pathway |
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Term
| What is response in signaling pathways? |
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Definition
| activation of cellular response |
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Term
| Why is reception typically done by membrane-spanning proteins? |
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Definition
Receptor changes shape, develops new activity
Channel
Enzymatic
Docking |
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Term
| Describe the process of reception |
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Definition
| a signaling molecule comes to the channel receptor, the gate opens, the signaling molecule docks and turns into a dimer, it then uses 6 atp to adp to turn fully activated. Then inactive relay proteins approach the dimer and turn active. Once there is a g protein-coupled receptor at the membrane, an inactive g protein is nearby followed with an enzyme. a signaling molecule activates the receptor, using gtp releasing the gdp and then the g protein now being active going the the enzyme, activates it, and causes a cellular response. |
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Term
| What is an exception of reception where it is not done by a membrane-spanning protein? |
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Definition
Some signals can cross
membrane in their own
Intracellular reception
Steroids
Nitric oxide (·NO) |
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Term
| What does signal transduction do and describe the process |
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Definition
Takes message from membrane to site of cellular
response
Kinase cascade
Second messenger
Soluble compound that migrates to site of action |
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Term
| How many steps are in the multistep signaling cascades? |
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Definition
| multiple, which allow for signal amplication |
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Term
| What are the two main targets for cellular response? |
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Definition
◦ Two main targets:
Gene regulation – production
Regulation of activity – post-production, Frequently via phosphorylation or Ca2+ |
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Term
| What is cell signaling specificity? |
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Definition
| Pattern of signaling differs in different cell types |
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Term
| What are the 5 responses for cell signaling specificity? |
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Definition
Response 1: Pathway leads to signaling response
Response 2 and 3: Pathway branches leading to two responses
Response 4:cross-talk occurs between two pathways
Response 5:different receptor leads to a different response |
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Term
| What do scaffolds do in cell signaling? |
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Definition
| greater specificity and greater efficiency |
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Term
| Describe a coordinated system |
|
Definition
◦ Calcium pumps move calcium out of cell and into smooth ER against
concentration gradient
◦ A neurotransmitter (signal from a neuron) activates calcium channels in
plasma membrane, causing an influx of extracellular calcium
◦ That calcium binds to and opens calcium channels on the SER, leading to a
massive burst of cytoplasmic calcium
◦ The muscle protein myosin is turned on by the calcium. This pulls the actin
microfilaments toward each other: the muscle contracts |
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Term
|
Definition
|
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Term
| where does apoptosis occur? |
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Definition
| in response to cell signaling |
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Term
| Why would you want apoptosis to occur? |
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Definition
• Kill off damaged or malfunctioning cells
• Remove unwanted cells |
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