Term
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Definition
Allows populations of prokaryotes to coordinate activities.
Allows coordination of tissue function in eucaryotes.
Allows a cell to respond appropriatly to a stimulus. |
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Term
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Definition
| Use chemicals to communicate and to aggregate. |
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Term
| Mechanisms of Cell-to-Cell Comunication |
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Definition
Local signalling by contact.
Local signalling by chemicals (paracrine and synaptic).
Long distance signalling (hormones). |
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Term
| Three Stages of Cell-to-Cell Communication |
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Definition
Reception of Signal
Transduction of Signal
Response to Signal |
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Term
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Definition
| Often involves the binding of a ligand (ligand=binds to a cellular) to a receptor causing the receptor to change shape/function. |
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Term
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Definition
| Altered receptor causes changes in intracellular proteins, often producing a second messenger. Some transduction systems may have a direct effect on gene activity or may directly enter cell. |
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Term
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Definition
| Second messanger causes a change in cell behaviour. |
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Term
| Tyrosine Kinase Receptors |
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Definition
1. Binding of ligand (first messanger) causes receptors to pair up, forming dimers.
2. Receptor molecules phosphorolate each other (autophosphorolation).
3. Phosphorolated receptor interacts with and activates relay proteins.
4. Activated relay proteins initiate a phosphorolation cascade. |
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Term
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Definition
| Binding of ligand causes receptor to allow ions to flow into cytoplasm. Increased ion concentration causes response (such as Ca2+ ions causing a contraction in a muscle cell). |
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Term
| G-Protein Coupled Receptors |
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Definition
| Binding of ligand causes the receptor to activate a G-Protein, the G-Protein then activates an enzyme. The enzyme is either adenylyl cyclase or phospholipase c. Phospholipase c breaks down phospholipids in the membrane. Breaks PIP2 into DAG (diacylglycerol) and IP3 (Inosital Triphosphate). |
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Term
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Definition
| Stimulates target cells to import glucose by producing GLUT-4 proteins. |
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Term
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Definition
Type 1: Little or no insulin is produced, target cells are not stimulated to import glucose.
Type 2: A protein in the glucose uptake cascade is deffective (a deffect in the liver cells). |
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