Chapter 11 Vocab - Summary Campbell Biology PDF

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Chapter 11: Cell Communication 11.1 “External signals are converted into responses within the cell” Evolution of Cell Signaling 

Signal transduction pathway - a series of steps linking a mechanical, chemical, or electrical stimulus to a specific cellular response Local and Long-Distance Signaling

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Local regulators- a secreted molecule that influences cells near where it is secreted

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Hormones- in multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the body, changing the target cells' functioning. Hormones are thus important in long-distance signaling 11.2 “Reception: A signal molecule binds to a receptor protein, causing it to change shape”

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Ligand- a molecule that binds specifically to another molecule, usually a larger one Receptors in the Plasma Membrane

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G protein-coupled receptor- a signal receptor protein in the plasma membrane that responds to the binding of a signaling molecule by activating a G protein. Also called a G protein-linked receptor

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G protein- a GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G protein-coupled receptor, to other signal transduction proteins inside the cell

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Receptor tyrosine kinases (RTK) - a receptor protein in the plasma membrane that responds to the binding of a signal molecule by catalyzing the transfer of phosphate groups from ATP to tyrosines on the cytoplasmic side of the receptor. The phosphorylated tyrosines activate other signal transduction proteins within the cell

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Ligand-gated ion channel- a transmembrane protein containing a pore that opens or closes as it changes shape in response to a signaling molecule (ligand), allowing or blocking the flow of specific ions; also called an ionotropic receptor 11.3 “Transduction: Cascades of molecular interactions relay signals from receptors to target molecules in the cell” Protein Phosphorylation and Dephosphorylation

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Protein kinase- an enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein

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Protein phosphatases- an enzyme that removes phosphate groups from (dephosphorylates) proteins, often functioning to reverse the effect of a protein kinase Small Molecules and Ions as Second Messengers

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Second messengers - a small, nonprotein, water-soluble molecule or ion, such as a calcium ion (Ca2+) or cyclic AMP, that relays a signal to a cell's interior in response to a signaling molecule bound by a single receptor protein

Cyclic AMP

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Cyclic AMP (cAMP)- cyclic adenosine mono phosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule (second messenger) in eukaryotic cells. It's also a regulator of some bacterial operons

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Adenylyl cyclase- an enzyme that converts ATP to cyclic AMP in response to an extracellular signal Calcium Ions and Inositol Triphosphate (IP3)

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Inositol triphosphate (IP3)- a second messenger that functions as an intermediate between certain signaling molecules and a subsequent second messenger, Ca2+, by causing a rise in cytoplasmic Ca2+ concentration

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Diacylglycerol (DAG)- a second messenger produced by the cleavage of the phospholipid PIP2 in the plasma membrane 11.4 “Response: Cell signaling leads to regulation of cytoplasmic activities or transcription”

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Scaffolding proteins- a type of large relay protein to which several other relay proteins are simultaneously attached, increasing the efficiency of signal transduction...