Term
| What is a signal transduction pathway |
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Definition
| The process by which a signal on a cell's surface is converted to a specific cellular response in a series of steps. |
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Term
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Definition
| A cell or small organism like bacteria can follow a chemical trail by reacting to whichever side of the cell has had the most receptors activated. |
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Term
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Definition
Aggregations of bacteria that often form recognizable structures containing regions of specialized function
Sometimes called Slime
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Term
There are three kinds of communication between cells:
Direct Contact - 2 kinds
Local Signalling - 2 kinds
Long-distance - 1 kind
Name all five kinds |
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Definition
Cell junctions
Cell-Cell Recognition
Paracrine signaling
Synaptic signaling
hormonal signaling
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Term
| What are the three stages of cell signaling |
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Definition
Reception
Transduction
Response
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Term
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Definition
| A molecule that specifically binds to another, usually larger, molecule |
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Term
| Name three kinds of cell membrane receptors |
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Definition
G-Protein Coupled
Receptor Tyrosine Kinases
Ion Channel Receptors
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Term
| What kinds of signaling molecules cannot enter the cell and must bind to cell membrane receptors |
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Definition
| Water soluble molecules cannot enter the cell and some molecules are too large to slip into the cell |
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Term
| What kinds of signaling molecules enter the cell and must bind to receptors in the cytoplasm or the nucleus |
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Definition
| Hydrophobic Molecules and molecules that are small enough to slip into the cell such as steroids & nitric oxide |
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Term
| What are the steps of G-Protein Coupled Reception |
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Definition
Inactive State
G-Protein is bound to GDP (guanosine di-phosphate)
Reception
Signaling molecule binds to the extracellular side of the cell membrane receptor.
Transduction
the receptor modifies its shape so that it binds a G-Protein to the cytoplasmic side.
the G-Protein binds to a GTP which displaces its GDP and activates the G-Protein.
Response
The G-Protein disassociates from the receptor and moves across the cell membrane to an enzyme and alters its shape. This enzyme will then trigger further cell response.
Recharge
The G-Protein is also a GTPase enzyme so it hydrolyzes its bound GTP to GDP and releases a phosphorus. The G-Protein then returns to its inactive state.
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Term
| What are the steps involved in Receptor Tyrosine Kinases signal transduction through the cell membrane |
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Definition
Reception
Signaling molecule binds to the Ligand binding sites on a pair of tyrosine kinase proteins
Transduction
The pair of tyrosine kinase proteins associate with each other and form a dimer
The Tyrosine kinase dimer adds six ATP to its tyrosine tail domain
Cellular Response
Receptor proteins inside the cell bind to a phosphorylated tyrosine domain. The activated receptor proteins then trigger cellular response.
This receptor, unlike the G-Protein receptor, can activate many cellular responses with each activiation because of its multiple binding domains.
Recharge
Phosphate is released, dimer disassociates, and two tyrosine kinases move apart. |
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Term
| How does a signaling molecule interact with an intracellular receptor? |
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Definition
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Term
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Definition
| The general term for an enzyme that transfers a phosphate group from ATP to a protein, thus phosphorylating the protein. |
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Term
| What is protein phosphatase |
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Definition
| An enzyme that (dephosphorylates) removes phosphate groups from proteins, often functioning to revers the effect of a protein kinase. |
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Term
| What are second messengers |
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Definition
A small, nonprotein, water-soluble molecule or ion, such as calcium ion (Ca2+) or cyclic AMP.
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