AP Biology Chapter 11 (Cell communication Flashcards

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