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
| 8307861519 | amplification | The strengthening of stimulus energy during transduction. |  | 0 |
| 8307861520 | 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 |
| 8307861521 | cytoplasm | The contents of the cell, exclusive of the nucleus and bounded by the plasma membrane. | 2 | |
| 8307861522 | 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 | |
| 8307861523 | 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 |
| 8307861524 | gap junction | A type of intercellular junction in animals that allows the passage of materials between cells. |  | 5 |
| 8307861525 | glycogen | An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch. | 6 | |
| 8307861526 | 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 | |
| 8307861527 | 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 |
| 8307861528 | local regulator | A secreted molecule that influences cells near where it is secreted. Used in paracrine and synaptic signaling. |  | 9 |
| 8307861529 | protein kinase | An enzyme that transfers phosphate groups from ATP to a protein, thus phosphorylating the protein. | 10 | |
| 8307861530 | protein phosphatase | An enzyme that removes phosphate groups from (dephosphorylates) proteins, often functioning to reverse the effect of a protein kinase. | 11 | |
| 8307861531 | 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 |
| 8307861532 | scaffolding protein | A type of large relay protein to which several other relay proteins are simultaneously attached, increasing the efficiency of signal transduction. |  | 13 |
| 8307861533 | 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 | |
| 8307861534 | signal transduction | The linkage of a mechanical, chemical, or electromagnetic stimulus to a specific cellular response. | 15 | |
| 8307861535 | 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 | |
| 8307861536 | 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 |
| 8307861537 | 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 |
| 8307861538 | 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 |
| 8307861539 | 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 |
| 8307861540 | signal transduction pathway | The process by which a signal on a cell's surface is converted into a specific cellular response. |  | 21 |
| 8307861541 | local regulators | These regulators influence cells in the vicinity of them. |  | 22 |
| 8307861542 | hormones | Circulating chemical signals that are formed in specialized cells, travel in body fluids, and act on specific target cells. |  | 23 |
| 8307861543 | ligand | A molecule that specifically binds to another molecule, often a larger one. |  | 24 |
| 8307861544 | protein kinase | The enzyme that transfers phosphate groups from ATP to protein. |  | 25 |
| 8307861545 | protein phosphatases | Enzymes that can rapidly remove phosphate groups from proteins. |  | 26 |
| 8307861546 | second messengers | Small, non-protein water soluble molecules or ions that send messages throughout the cells by diffusion. |  | 27 |
| 8307861547 | reception | The target cell's detection of a signal molecule coming from outside the cell. |  | 28 |
| 8307861548 | transduction | The binding of the signal molecule changes the receptor protein in some way. |  | 29 |
| 8307861549 | response | The transduced signal finally triggers a specific cellular response. |  | 30 |
| 8307861550 | G-protein-linked receptor | A plasma membrane receptor that works with the help of a G-protein. |  | 31 |
| 8307861551 | 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 |
| 8307861552 | ligand-gated ion channel | Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape. |  | 33 |
