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
| 5739622996 | amplification | The strengthening of stimulus energy during transduction. |  | 0 |
| 5739622997 | 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 |
| 5739622998 | cytoplasm | The contents of the cell, exclusive of the nucleus and bounded by the plasma membrane. | 2 | |
| 5739622999 | diacylglycerol (DAG) | A second messenger produced by the cleavage of a certain kind of phospholipid in the plasma membrane. |  | 3 |
| 5739623000 | 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. | 4 | |
| 5739623001 | 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. |  | 5 |
| 5739623002 | gap junction | A type of intercellular junction in animals that allows the passage of materials between cells. |  | 6 |
| 5739623003 | glycogen | An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch. | 7 | |
| 5739623004 | growth factor | (1) A protein that must be present in the extracellular environment (culture medium or animal body) for the growth and normal development of certain types of cells. (2) A local regulator that acts on nearby cells to stimulate cell proliferation and differentiation. | 8 | |
| 5739623005 | inositol trisphosphate (IP3) | A second messenger that functions as an intermediate between certain nonsteroid hormones and a third messenger, a rise in cytoplasmic Ca2+ concentration. | | 9 |
| 5739623006 | 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. | 10 | |
| 5739623007 | 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. |  | 11 |
| 5739623008 | local regulator | A secreted molecule that influences cells near where it is secreted. Used in paracrine and synaptic signaling. |  | 12 |
| 5739623010 | protein kinase | An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein. | 13 | |
| 5739623011 | protein phosphatase | An enzyme that removes phosphate groups from (dephosphorylates) proteins, often functioning to reverse the effect of a protein kinase. | 14 | |
| 5739623012 | 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. |  | 15 |
| 5739623013 | scaffolding protein | A type of large relay protein to which several other relay proteins are simultaneously attached, increasing the efficiency of signal transduction. |  | 16 |
| 5739623014 | 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. | 17 | |
| 5739623015 | signal transduction | The linkage of a mechanical, chemical, or electromagnetic stimulus to a specific cellular response. | 18 | |
| 5739623016 | 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). | 19 | |
| 5739623017 | 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. |  | 20 |
| 5739623018 | 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. | | 21 |
| 5739623019 | yeast | Single-celled fungus that reproduces asexually by binary fission or by the pinching of small buds off a parent cell; some species exhibit cell fusion between different mating types. |  | 22 |
| 5739623020 | three stages of cell communication | reception - receptor responds to binding of ligand molecule; transduction - translation and amplification of message; response - activation of cellular response |  | 23 |
| 5739623021 | 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. |  | 24 |
| 5739623022 | signal transduction pathway | The process by which a signal on a cell's surface is converted into a specific cellular response. |  | 25 |
| 5739623023 | local regulators | These regulators influence cells in the vicinity of them. |  | 26 |
| 5739623024 | hormones | Circulating chemical signals that are formed in specialized cells, travel in body fluids, and act on specific target cells. |  | 27 |
| 5739623025 | ligand | A molecule that specifically binds to another molecule, often a larger one. |  | 28 |
| 5739623026 | protein kinase | The enzyme that transfers phosphate groups from ATP to protein. |  | 29 |
| 5739623027 | adenylyl cyclase | Converts ATP to cyclic AMP in response to an extracellular signal. |  | 30 |
| 5739623030 | reception | The target cell's detection of a signal molecule coming from outside the cell. |  | 31 |
| 5739623031 | transduction | The binding of the signal molecule changes the receptor protein in some way. |  | 32 |
| 5739623032 | response | The transduced signal finally triggers a specific cellular response. |  | 33 |
| 5739623033 | G-protein-linked receptor | A plasma membrane receptor that works with the help of a G-protein. |  | 34 |
| 5739623034 | 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. |  | 35 |
| 5739623035 | ligand-gated ion channel | Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape. |  | 36 |
| 5744780695 | quorum sensing | the regulation of gene expression in response to fluctuations in cell-population density |  | 37 |
| 5744787937 | biofilms | aggregations of bacteria that often form recognizable structures containing regions of specialized functions (ie. fruiting bodies) |  | 38 |
| 5744798667 | paracrine signaling | a form of cell- to-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behavior or differentiation of those cells. |  | 39 |
| 5744801168 | autocrine signaling | form of cell signaling in which a cell secretes a hormone or chemical messenger that binds to a receptor on the same cell leading to changes in the cell |  | 40 |
| 5744804207 | juxtacrine signaling | Type of cell to cell signalling in multicellular organisms that requires close contact (AKA contact-dependent signalling) | 41 | |
| 5744809077 | synaptic signalling | Type of signalling that occurs over a very short distance called a synapse such as between 2 neurons. | 42 | |
| 5744816881 | Dimer | This is formed when two receptor polypeptides associate closely with each other | 43 | |
| 5744825813 | cAMP | Common second messenger which is a derivative of ATP and used for intracellular signal transduction in many different organisms |  | 44 |
