Campbell Biology Chapter 11 Exam Solved

Campbell Biology Chapter 11 Exam Solved Adenylyl cyclase - Answer- an enzyme embedded in the plasma membrane which converts ATP to cAMP in response to an extracellular signal apoptosis - Answer- a type of cell death in which the cell uses specialized cellular machinery to kill itself Cyclic AMP - Answer- Cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule (second messenger) in eukaryotic cells (for example, in vertebrate endocrine cells). It is also a regulator of some bacterial operons. diacylglycerol (DAG) - Answer- A second messenger produced by the cleavage of a certain kind of phospholipid in the plasma membrane. G protein - Answer- 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. G Protein-coupled receptor - Answer- 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. Adenylyl cyclase - Answer- an enzyme embedded in the plasma membrane which converts ATP to cAMP in response to an extracellular signal apoptosis - Answer- a type of cell death in which the cell uses specialized cellular machinery to kill itself hormone - Answer- a chemical that serves as a messenger. Each hormone is secreted by a gland and travels to one or more target organs, where it brings about responses. inositol triphosphate - Answer- A second messenger that functions as an intermediate between certain nonsteroid hormones and a third messenger, a rise in cytoplasmic Ca 2+ concentration. ligand - Answer- A molecule that binds specifically to a receptor site of another molecule. ligand-gated ion channel - Answer- A protein pore in the plasma membrane that opens or closes in response to a chemical signal, allowing or blocking the flow of specific ions. protein kinase - Answer- An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein. local regulator - Answer- A secreted molecule that influences cells near where it is secreted. protein phosphatase - Answer- An enzyme that removes phosphate groups from proteins, often functioning to reverse the effect of a protein kinase. receptor tyrosine kinase - Answer- 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 tryrosines on the cyoplasmic side of the receptor. The phosphorylated tryrosines activate other signal transduction proteins within the cell. scaffolding protein - Answer- A type of large relay protein to which several other relay proteins are simultaneously attached to increase the efficiency of signal transduction. second messenger - Answer- A small, nonprotein, water-soluble molecule or ion, such as calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signal received by a signal receptor protein. signal transduction pathway - Answer- A series of steps linking a mechanical, chemical, or electromagnetic stimulus to a specific cellular response.