Term
|
Definition
| converts signals on a cells surface into cellular responses; communicate via chemical messengers; suggests early origin |
|
|
Term
|
Definition
| refers to signal reception and transduction |
|
|
Term
|
Definition
| signal molecules that are broadcasted throughout the entire body via the bloodstream |
|
|
Term
|
Definition
| signal molecules diffuse locally through extracellular fluid; stays near the cell that secreted them |
|
|
Term
|
Definition
| extracellular signal molecules released by nerve terminals when stimulated |
|
|
Term
|
Definition
| (receptor) activated by only one type of signal; restricts the types of signals that can affect the cell |
|
|
Term
| Extracellular Signal Molecules |
|
Definition
| two classes: 1) molecules too large or too hydrophilic to cross the plasma membrane 2) small or hydrophobic molecules that can easily cross the plasma membrane |
|
|
Term
|
Definition
| intracellular receptor proteins including cortisol, estradiol, testosterone and thyroxine. |
|
|
Term
|
Definition
| (NO) dissolved gaseous neurotransmitter that is very fast acting |
|
|
Term
| Intracellular Signaling Molecule |
|
Definition
| each cell activates or generates the next signaling molecule in the pathway until a metabolic enzyme is kicked into action causing a morphological change in the cytoskeleton causing the gene to turn on or off |
|
|
Term
| Intracellular Signaling Pathways |
|
Definition
| 1) relays signals to spread it throughout the cell 2) amplifies the signal received to evoke a large intracellular response 3) integrates cells from multiple cells before relaying the signal 4) distributes the signal to more than one signaling pathway or effector protein |
|
|
Term
|
Definition
| receipt of a signal causes them to toggle from an inactive to an active state |
|
|
Term
|
Definition
| tacks a phosphate group onto the switch protein |
|
|
Term
|
Definition
| plucks the phosphate group off of the switch protein |
|
|
Term
|
Definition
| operates in intracellular signaling pathways; phosphorylates proteins on serines or threonines |
|
|
Term
|
Definition
| intracellular signaling pathway; phosphorylates proteins on tyrosines |
|
|
Term
|
Definition
| intracellular signaling pathway; switch between an active and an inactive state depending on whether they have GTP or GDP bound to them, respectively. They shut themselves off by hydrolyzing their bound GTP to GDP. |
|
|
Term
| Ion-Channel-Coupled Receptors |
|
Definition
| AKA: transmitter-gated ion channels; responsible for the rapid transmission of signals across synapses in the nervous system |
|
|
Term
| G-Protein-Coupled Receptors |
|
Definition
| GPCRs; forms the largest family of cell-surface receptors; mediate responses to an enormous diversity of extracellular signal molecules, including hormones, local mediators, and neurotransmitters |
|
|
Term
|
Definition
| composed of 3 protein subunits; α,β, and γ, 2 of which are tethered to the plasma membrane by short lipid tails; second messenger |
|
|
Term
|
Definition
| AKA: second messengers; small intracellular signaling molecules generated in cascade events; prouced in large numbers when a membrane-bound enzyme is activated, rapidly diffuse away from their source spreading the signal |
|
|
Term
|
Definition
| enzyme that alters the concentration of cyclic AMP within the cell |
|
|
Term
|
Definition
| synthesized from ATP; G-protein |
|
|
Term
| Cyclic-AMP-Dependent Protein Kinase |
|
Definition
| (PKA) enzyme is normally inactive in a complex with another protein; catalyzes the phosphorylation of particular serines or threonines on certain intracellular proteins, altering the activity of the proteins |
|
|
Term
|
Definition
| propagates a signal by cleaving a lipid molecule that is a component of the plasma membrane |
|
|
Term
|
Definition
| the molecule that phospholipase C cleaves; a phopholipid with the sugar inositol attached to its head; present in small quantities in the cytosolic half of the membrane lipid bilayer |
|
|
Term
| Inositol 1,4,5-Triphosphate |
|
Definition
| (IP3) one of two second messenger molecules generated with the action of phospholipase C |
|
|
Term
|
Definition
| (DAG) one of two second messengers generated with the action of phospholipase C |
|
|
Term
|
Definition
| (PKC) enzyme that translocated from the cytosol to the plamsa membrane; requires Ca++ to become active |
|
|
Term
|
Definition
| most widespread and common Ca++ responsive protein; present in the cytosol of all eucaryotic cells |
|
|
Term
| Ca++/ Calmodulin-Dependent Protein Kinases |
|
Definition
| (CaM- Kinases) an important class of targets for calmodulin; influence other processes in the cell by phosphorylating selected proteins |
|
|
Term
|
Definition
| frequently occurs in signaling pathways that respond to chemical signals; allows cells to remain sensitive to changes of signal intensity over a wide range of background levels of stimulation |
|
|
Term
| Enzyme- Coupled Receptors |
|
Definition
| transmembrane proteins that display their ligand-binding domains on the outer surface of the plasma membrane |
|
|
Term
| Receptor Tyrosine Kinases |
|
Definition
| (RTKs) enzyme-coupled receptor with a cytoplasmic domain; phosphorylates specific tyrosines on selected intracellular proteins |
|
|
Term
|
Definition
| a small GTP binding protein that is bound by a lipid tail to the cytoplasmic face of the plasma membrane;activated by virtually all RTKs |
|
|
Term
|
Definition
| family of small GTP-binding proteins |
|
|
Term
| MAP-Kinase Signaling Module |
|
Definition
|
|
Term
|
Definition
| the final kinase in the chain; mitogen-activated protein Kinase |
|
|
Term
| Phosphoinositide 3-Kinase |
|
Definition
| (PI 3-kinanse) promotes cell growth and survival; phosphorylates inositol phospholipids in the plasma membrane |
|
|
Term
|
Definition
| hormones and local mediators; bind to receptors that can activate transcription regulators that are held in a latent state near the plasma membrane |
|
|
Term
|
Definition
| an intricate network of protein filaments that extends throughout the cytoplasm |
|
|
Term
|
Definition
| have great tensile strength; main function is to enable cells to withstand the mechanical stress that occurs when cells are stretched (e.g. skin) |
|
|
Term
|
Definition
| constructed from a class of intermediate filament proteins call lamins |
|
|
Term
|
Definition
| crucial in organizing role of all eucaryotic cells; long, stiff, hollow tubes of protein that can rapidly disassemble in one location and reassemble in another |
|
|
Term
|
Definition
| the directional arrow embodied in the structure |
|
|
Term
|
Definition
| organizes the array of microtubules that radiates outward from it through the cytoplasm (important in cell division) |
|
|
Term
|
Definition
| made of cylindrical array of short microtubules; no role in the nucleation of microtubules in the centromere; function unknown |
|
|
Term
|
Definition
| stems from the capacity of tubulin molecules to hydrolyze GTP; causes microtubules to grow and shrink rapidly |
|
|
Term
|
Definition
| use the energy derived from repeated cycles of ATP hydrolysis to travel steadily along the actin filament or the microtubule in a single direction |
|
|
Term
|
Definition
| generally move toward the plus end of a microtubule (away from the centrosome) |
|
|
Term
|
Definition
| move toward the minus end (toward the centrosome) |
|
|
Term
|
Definition
| hairlike structures about 0.25 um in diameter, covered by plasma membrane, extends from the surface of many kinds of eukaryotic cells |
|
|
Term
|
Definition
| propel sperm and many protozoa; similar to cilia in internal structure, but are usually much longer; designed to move the entire cell, not create a current |
|
|
Term
|
Definition
| found in all eucaryotic cells are are essential for many of their movements, especially those involving the cell surface |
|
|
Term
|
Definition
| area of high concentration of actin just beneath the plasma membrane; actin filaments are linked by actin-binding proteins into a meshwork that supports the outer surface of the cell and gives it mechanical strength |
|
|
Term
|
Definition
| contains a dense meshwork of actin filaments oriented so that most of the filaments have their plus ends close to the plasma membrane |
|
|
Term
|
Definition
| thin, still protrusions similar to lamellipodia |
|
|
Term
|
Definition
| actin-dependent motor proteins belong to this family; binds to and hydrolyzes ATP, providing energy for their movement along actin filaments from the minus end toward the plus end |
|
|
Term
|
Definition
| GTP-binding proteins; molecular switches that control cellular processes by cycling between an active GTP-bound state and an inactive GDP-bound state |
|
|
Term
|
Definition
| myofibrils are made up of these tiny contractile units; composed of actin and myosin |
|
|
Term
|
Definition
| the essential mechanism by which all living things reproduce |
|
|
Term
|
Definition
| phase of the cell cycle including mitosis and cytokinesis |
|
|
Term
|
Definition
| the period between one M phase and the next |
|
|
Term
|
Definition
| (synthesis) cell replicates its nuclear DNA, essential prerequisite for cell division |
|
|
Term
|
Definition
| (Gap) interval between the completion of M phase and the beginning of S phase |
|
|
Term
|
Definition
| interval between the end of S phase and the beginning of M phase |
|
|
Term
|
Definition
| molecular brakes that can stop the mitotic cycle; does not trigger the next step unless the cell is properly prepared |
|
|
Term
| Cell-Cycle Control System |
|
Definition
| switches machinery on and off at the correct times and thereby coordinates the various steps of the cell cycle |
|
|
Term
|
Definition
| responsible, in part, for switching kinases on and off at the appropriate times |
|
|
Term
| Cyclin-Dependent Protein Kinases |
|
Definition
| (Cdks) the kinases of the cell-cycle control system; concentrations vary in a cyclical fashion during the cell cycle |
|
|
Term
|
Definition
| acts in G2 to trigger entry into M phase |
|
|
Term
|
Definition
| active complex M cyclin forms with it's Cdk |
|
|
Term
| S-Cyclins and G1/S Cyclins |
|
Definition
| binds to distinct Cdk proteins late in G1 to form S-Cdk and G1/S-Cdk; triggers S phase |
|
|
Term
|
Definition
| act early in G1 and bind to other Cdk proteins to form G1-Cdks |
|
|
Term
|
Definition
| helps drive the cell through G1 toward S phase |
|
|
Term
|
Definition
| blocks the assembly or activity of one or more cyclin-Cdk complexes |
|
|
Term
| Origin recognition Complex |
|
Definition
| (ORC) a multiprotein complex that remains bound to origins of replication throughout the cell cycle; serves as a landing pad for additional regulatory proteins that bind before the start of S phase |
|
|
Term
|
Definition
| two copies of each replicated chromosome that remain bound together |
|
|
Term
|
Definition
| assemble along the length of each sister chromatid as the DNA is replicated in S phase |
|
|
Term
|
Definition
| a transcription regulator that activates the transcription of a gene encoding a Cdk inhibitor protein called p21 |
|
|
Term
|
Definition
| protein complexes that allows chromosomes to condense |
|
|
Term
|
Definition
| period in which the chromosomes are visible (because they are condensed) |
|
|
Term
|
Definition
| principal microtubule-organizing center in animal cells |
|
|
Term
|
Definition
| a radial array of microtubules that forms as two centrosomes separate |
|
|
Term
|
Definition
| mitotic spindle begins to form |
|
|
Term
|
Definition
| two sets of microtubules that maintains the bipolar shape of a replicating cell |
|
|
Term
|
Definition
| two centrosomes give rise to microtubues that interact; called interpolar microtubules |
|
|
Term
|
Definition
| starts abruptly with the disassembly of the nuclear envelope, which breaks up into small membrane vesicles |
|
|
Term
|
Definition
| assemble on the condensed chromosomes during late prophase |
|
|
Term
|
Definition
| generated tension on the kinetochores, which are being pulled in opposite directions |
|
|
Term
|
Definition
| chromosomes align at the equator of the spindle, halfway between the two spindle poles |
|
|
Term
|
Definition
| begins abruptly with the release of the cohesin linkage that holds the sister chromatids together |
|
|
Term
| Anaphase-Promoting Complex |
|
Definition
| (APC) securin is targeted for destruction by this protein complex at the beginning of anaphase; allows for separase to break the cohesin linkages |
|
|
Term
|
Definition
| final stage of mitosis; mitotic spindle disassembles, nuclear envelop reassembles around each group of chromosomes to form daughter nuclei. |
|
|
Term
|
Definition
| the process by which the cytoplasm is cleaved in two, completes M phase |
|
|
Term
|
Definition
| the assembly process of a cell wall is guided by this structure, which is formed by the remains of the interpolar microtubules at the equator of the old mitotic spindle |
|
|
Term
|
Definition
| programed cell death "falling off" |
|
|
Term
|
Definition
| machinery responsible for apoptosis; part of the family of proteases |
|
|
Term
|
Definition
| main proteins that regulate the activation of procaspases; intracellular proteins |
|
|
Term
|
Definition
| promote cell survival, largely by suppressing apoptosis |
|
|
Term
|
Definition
| stimulate cell division, primarily by overcoming the intracellular braking mechanisms that tend to block progression through the cell cycle |
|
|
Term
|
Definition
| stimulate cell growth by promoting the synthesis and inhibiting the degradation of proteins and other macromolecules |
|
|
Term
|
Definition
| simple and direct, gives rise to offspring that are genetically identical to parent organisms |
|
|
Term
|
Definition
| involves the mixing of genomes from two individuals to produce offspring that are genetically distinct from one another and from both parents |
|
|
Term
|
Definition
| specialized chromosomes that distinguish males from females |
|
|
Term
|
Definition
| variant versions of a gene |
|
|
Term
|
Definition
| AKA: gametes; haploid cells |
|
|
Term
|
Definition
|
|
Term
|
Definition
| all cells not for sex determination; body cells |
|
|
Term
|
Definition
| carries only a single set of chromosomes |
|
|
Term
|
Definition
| carries two sets of chromosomes |
|
|
Term
|
Definition
| describes the cellular division from diploid cells to haploid cells |
|
|
Term
|
Definition
| remain tightly linked along their length |
|
|
Term
|
Definition
| AKA: homologs; physical pairing of matched sets of chromosomes |
|
|
Term
|
Definition
| initial association of homologs |
|
|
Term
|
Definition
| the structure formed when duplicated chromosomes pair (tetrad) |
|
|
Term
|
Definition
| a process in which an exchange of DNA occurs between two identical or very similar nucleotide sequences |
|
|
Term
|
Definition
| recombination resulting from a physical swap of homologous segments form the maternal and paternal chromosomes |
|
|
Term
|
Definition
| portion of the chromosome that holds duplicated homologs together |
|
|
Term
|
Definition
| gametes that come together to form a zygote |
|
|
Term
|
Definition
|
|
Term
|
Definition
| alternate versions of a gene |
|
|
Term
|
Definition
| the whole collection of alleles possessed by an individual |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| the appearance; physical expression of a genotype |
|
|
Term
|
Definition
| states that the two alleles for each trait separate during gamete formation and that they then unite at random (one from each parent) at fertilization |
|
|
Term
|
Definition
| shows the phenotype of each family member for the relevant trait |
|
|
Term
| Law of Independent Assortment |
|
Definition
| the independent segregation of each pair of alleles during gamete formation |
|
|
Term
| Loss-of-Function Mutations |
|
Definition
| changes the reduce or eliminate the activity of a gene |
|
|
Term
| Gain-of-Function Mutations |
|
Definition
| usually dominant; produces proteins that are overactive or are active in inappropriate circumstances |
|
|
Term
|
Definition
| involves examining many thousands of mutagenized individuals to find those few who show a specific altered phenotype of interest |
|
|
Term
|
Definition
| reveals whether the mutations fall in the same gene or in different genes |
|
|
Term
|
Definition
| two or more sequence variants coexits in the population and are both common |
|
|
Term
| Single-Nucleotide Polymorphisms |
|
Definition
| (SNPs) used as markers for building genetic maps or for conducting searches for mutations that correlate with specific diseases or predispositions to disease |
|
|
Term
|
Definition
| linked to their nearest neighbors in blocks; tend to be inherited as a unit |
|
|
