AP Biology: Cell Communication Flashcards

Cell Communication
Vocabulary: signal transduction pathway, quorum sensing, hormones, protein kinase, protein phosphatase, G proteins, cyclic AMP, first messengers, second messengers, signal amplification, apoptosis, paracrine signaling, synaptic signaling, hormonal signaling
1. Know the three stages of Cell Signaling:
a. Reception - receptors in the plasma membrane, intracellular receptors
b. Transduction - signal transduction pathways, phosphorylation and dephosporylation, second messengers
c. Response - nuclear and cytoplasmic responses; protein synthesis, ion channels, cell shape
2. Describe the relationship between signal molecules and cell surface receptors, and give examples of each.
3. Describe G-protein-linked receptors and receptor tyrosine kinases, and explain the role of each in receiving chemical signals and initiating signal transduction pathways.
4. Describe a signal transduction pathway and explain how this multi-step process can amplify the signal and lead to a cellular response.
5. Understand that different kinds of cells have different collections of proteins (p.221) and how this affects the response of a particular cell to a specific signaling molecule.
6. Define apoptosis and describe its importance and function(s) in an organism.

Terms : Hide Images [1]

9876596310	amplification	The strengthening of stimulus energy during transduction.	0
9876596311	apoptosis	A program of controlled cell suicide, which is brought about by signals that trigger the activation of a cascade of suicide proteins in the cell destined to die.	1
9876596312	cytoplasm	The contents of the cell, exclusive of the nucleus and bounded by the plasma membrane.	2
9876596313	epinephrine	water soluble ligand molecule; A catecholamine that, when secreted by the adrenal medulla, mediates "fight-or-flight" responses to short-term stresses; also released by some neurons as a neurotransmitter; also known as adrenaline.	3
9876596314	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.	4
9876596315	gap junction	A type of intercellular junction in animals that allows the passage of materials between cells.	5
9876596316	glycogen	An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.	6
9876596317	ligand	A molecule that binds specifically to another molecule; often first step in cell communication. Water soluble ligands typically do not enter cell. Lipid soluble ligands (such as steroids) do enter the cell.	7
9876596318	ligand-gated ion channel	A protein pore in cellular membranes that opens or closes in response to A signaling chemical (its ligand), allowing or blocking the flow of specific ions.	8
9876596319	local regulator	A secreted molecule that influences cells near where it is secreted. Used in paracrine and synaptic signaling.	9
9876596320	protein kinase	An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein.	10
9876596321	protein phosphatase	An enzyme that removes phosphate groups from (dephosphorylates) proteins, often functioning to reverse the effect of a protein kinase.	11
9876596322	receptor tyrosine kinase	A receptor protein in the plasma membrane, the cytoplasmic (intracellular) part of which can catalyze the transfer of a phosphate group from ATP to a tyrosine on another protein. Receptor tyrosine kinases often respond to the binding of a signaling molecule by dimerizing and then phosphorylating a tyrosine on the cytoplasmic portion of the other receptor in the dimer. The phosphorylated tyrosines on the receptors then activate other signal transduction proteins within the cell.	12
9876596323	scaffolding protein	A type of large relay protein to which several other relay proteins are simultaneously attached, increasing the efficiency of signal transduction.	13
9876596324	second messenger	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 signal receptor protein.	14
9876596325	signal transduction	The linkage of a mechanical, chemical, or electromagnetic stimulus to a specific cellular response.	15
9876596326	signal transduction pathway	A series of steps linking a mechanical or chemical stimulus to a specific cellular response. There are four types that we studied: g-protein linked reception; hormonal reception; receptor tyrosine kinase reception; pathways using second messengers (cAMP; calcium ions).	16
9876596327	testosterone	A steroid hormone required for development of the male reproductive system, spermatogenesis, and male secondary sex characteristics; the major androgen in mammals. Pathway illustrates the mechanism for all steroid hormones.	17
9876596328	transcription factor	A regulatory protein that binds to DNA and affects transcription of specific genes. The hormone-receptor complex becomes a transcription factor in the steroid transduction pathway.	18
9876596329	three stages of cell communication	reception - receptor responds to binding of ligand molecule; transduction - translation and amplification of message; response - activation of cellular response	19
9876596330	g-linked protein receptor	receives message for g-linked protein signaling pathway. Consists of seven alpha helices that span the plasma membrane. Changes shape when ligand molecule binds.	20
9876596331	signal transduction pathway	The process by which a signal on a cell's surface is converted into a specific cellular response.	21
9876596332	local regulators	These regulators influence cells in the vicinity of them.	22
9876596333	hormones	Circulating chemical signals that are formed in specialized cells, travel in body fluids, and act on specific target cells.	23
9876596334	ligand	A molecule that specifically binds to another molecule, often a larger one.	24
9876596335	protein kinase	The enzyme that transfers phosphate groups from ATP to protein.	25
9876596336	protein phosphatases	Enzymes that can rapidly remove phosphate groups from proteins.	26
9876596337	second messengers	Small, non-protein water soluble molecules or ions that send messages throughout the cells by diffusion.	27
9876596338	reception	The target cell's detection of a signal molecule coming from outside the cell.	28
9876596339	transduction	The binding of the signal molecule changes the receptor protein in some way.	29
9876596340	response	The transduced signal finally triggers a specific cellular response.	30
9876596341	G-protein-linked receptor	A plasma membrane receptor that works with the help of a G-protein.	31
9876596342	receptor tyrosine kinase	A receptor with enzymatic activity that can trigger more than one signal transduction pathway at once, helping the cell regulate and coordinate many aspects of cell growth and reproduction.	32
9876596343	ligand-gated ion channel	Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape.	33