Terms : Hide Images
| 495955330 | transduce... (whats the path called?) | external signals are changed into a form that brings about a response (signal transduction pathway) | |
| 495955331 | What are the cell junctions that allow nearby cells to communicate? | gap junctions in animals; plasmodesmata in plants | |
| 495955332 | messenger molecules (ie local regulators)...and what is this called | secreted by signaling cell travel short distance to a receiving cell; local signaling | |
| 495955333 | How does the animal nervous system communicate? | with electrical and chemical signals between a nerve cell and its target cell | |
| 495955334 | Hormones serve as... | long distance signals in plants and animals | |
| 495955335 | What are the 3 stages of cell signaling? | reception, transduction, response | |
| 495955336 | What is reception? | receives signal by target cell; specifically binds to a certain cell type (target cells); chemical signal (ligand) binds to a receptor; most of the receptors are cell membrane proteins because most signals are too big to diffuse through membrane | |
| 495955337 | What is transduction? | receptor protein's shape is changed by the binding of the chemical signal; binding causes changes to occur in the cell that will bring about a response | |
| 495955338 | Response | a specific cellular response is triggered | |
| 495955339 | G protein coupled receptors...(what are they, not how they work) | plasma membrane proteins with receptors on them; receives epinephrine, hormones, neurotransmitters | |
| 495955340 | How do G-Protein coupled receptors work? | chemical signal binds to G protein coupled receptor, receptor changes shape and binds to a G-protein inside of plasma membrane; G protein will give off its GDP and accept GTP and is activated; moves along inside of plasma membrane and binds to another membrane protein (enzyme) to activate it; this causes cell response | |
| 495955341 | How is a G-Protein coupled receptor turned off? | G protein acts as a GTPase and removes the P (Though hydrolysis), GTP to GDP | |
| 495955342 | Tyrosine-kinase receptors (what are they (kinase) not how) | plasma membrane receptors used by growth factors; kinase is an enzyme that transfers a phosphate group from one molecule to another (in this, transfer P from ATP to tyrosine on the tail) | |
| 495955343 | How do tyrosine-kinase receptors work? | 2 ligands bind to 2 tyrosine-kinase receptors; causes 2 receptors to bind together and form a dimer; activates the tail and they phosphorylate each other; other proteins bind to the phosphorylated tails and cause a cellular response; 1 dimer can activate 10 or more different proteins simultaneously; if they bind without a chemical signal, may cause cancer | |
| 495955344 | Ion channel receptors... | plasma membrane receptors, signal between nerve cells, have a gate that can open or close a channel; when ligand binds, the channel opens or closes, allowing flow or stopping flow of ions | |
| 495955345 | intracellular receptors | inside cell in cytosol or in nucleus; steroid and thyroid hormones, nitric oxide all use intracellular receptors; testosterone: binds to receptor and activates it; activated receptor enters nucleus, binds to DNa and acts as a transcription factor which makes DA make RNA and proteins | |
| 495955346 | signal transduction pathways | usually multistep pathways involving lots of P switching or moving of molecules that act as messengers; lots of protein-protein interactions | |
| 495955347 | protein phosphorylation | phosphorylation cascade; phosphorylation can usually increase or decrease the activity of a protein; protein phosphatases remove phosphates (dephosphorylates) to turn off signal | |
| 495955348 | second messengers: cyclic AMP (cAMP) | signal molecule (first messenger) binds to a cell membrane receptor, activates G protein which activates adenylyl cyclase which converts ATP to cAMP; cAMP activates other proteins to cause response; photodiesterase returns cAMP to AMP | |
| 495955349 | second messengers: calcium ions and inositol triphosphate: | signal molecules bind to either a G-linked protein receptor or a tyrosine-kinase receptor; produces IP3 which acts as second messenger; binds to ligand-gated calcium channel on the ER and opens it to release Ca ions which act as the second messenger and cause a response; calcium ions are actively pumped back onto the mitochondria, ER and outside the cell | |
| 495955350 | scaffolding proteins: | large relay proteins to which several other relay proteins are attached | |
| 495955351 | apoptosis | programmed cell death; cellular agents chop DNA, organelles, other cytoplasmic stuff; cell shrinks and becomes lobed (blebbing); cell's parts are packaged into vesicles and digested by scavenger cells; cleans up cells, helps in embryonic development, develop nervous system, immune system | |
| 495955352 | What creature where studies on apoptosis taken? | caenorhabditis elegans (nematode) | |
| 495955353 | What kind of signals are transduced when apoptosis occurs? | external- death sinaling ligand binds to receptor; internal- from nucleus in response to DNA damage, from ER in response to numerous misfolded proteins |
