Studied by 1 personapoptosis
programmed cell death
autocrine signal
signal that is sent and received by the same or similar nearby cells
autoinducer
signaling molecule secreted by bacteria to communicate with other bacteria of its kind and others
cell-surface receptor
cell-surface protein that transmits a signal from the exterior of the cell to the interior, even though the ligand does not enter the cell
chemical synapse
small space between axon terminals and dendrites of nerve cells where neurotransmitters function
cyclic AMP (cAMP)
second messenger that is derived from ATP
cyclic AMP-dependent kinase
(also, protein kinase A, or PKA) kinase that is activated by binding to cAMP
diacylglycerol (DAG)
cleavage product of PIP2 that is used for signaling within the plasma membrane
dimer
chemical compound formed when two molecules join together
dimerization
(of receptor proteins) interaction of two receptor proteins to form a functional complex called a dimer
endocrine cell
cell that releases ligands involved in endocrine signaling (hormones)
endocrine signal
long-distance signal that is delivered by ligands (hormones) traveling through an organisms circulatory system from the signaling cell to the target cell
enzyme-linked receptor
cell-surface receptor with intracellular domains that are associated with membrane-bound enzymes
extracellular domain
region of a cell-surface receptor that is located on the cell surface
G-protein-linked receptor
cell-surface receptor that activates membrane-bound G-proteins to transmit a signal from the receptor to nearby membrane components
growth factor
ligand that binds to cell-surface receptors and stimulates cell growth
inhibitor
molecule that binds to a protein (usually an enzyme) and keeps it from functioning
inositol phospholipid
lipid present at small concentrations in the plasma membrane that is converted into a second messenger; it has inositol (a carbohydrate) as its hydrophilic head group
inositol triphosphate (IP3)
cleavage product of PIP2 that is used for signaling within the cell
intercellular signaling
communication between cells
internal receptor
(also, intracellular receptor) receptor protein that is located in the cytosol of a cell and binds to ligands that pass through the plasma membrane
intracellular mediator
(also, second messenger) small molecule that transmits signals within a cell
intracellular signaling
communication within cells
ion channel-linked receptor
cell-surface receptor that forms a plasma membrane channel, which opens when a ligand binds to the extracellular domain (ligand-gated channels)
kinase
an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule.
ligand
molecule produced by a signaling cell that binds with a specific receptor, delivering a signal in the process
mating factor
signaling molecule secreted by yeast cells to communicate to nearby yeast cells that they are available to mate and communicating their mating orientation
neurotransmitter
chemical ligand that carries a signal from one nerve cell to the next
paracrine signal
signal between nearby cells that is delivered by ligands traveling in the liquid medium in the space between the cells
phosphatase
enzyme that removes the phosphate group from a molecule that has been previously phosphorylated
phosphodiesterase
enzyme that degrades cAMP, producing AMP, to terminate signaling
quorum sensing
method of cellular communication used by bacteria that informs them of the abundance of similar (or different) bacteria in the environment
receptor
protein in or on a target cell that bind to ligands
second messenger
small, non-protein molecule that propagates a signal within the cell after activation of a receptor causes its release
signal integration
interaction of signals from two or more different cell-surface receptors that merge to activate the same response in the cell
signal transduction
propagation of the signal through the cytoplasm (and sometimes also the nucleus) of the cell
signaling cell
cell that releases signal molecules that allow communication with another cell
signaling pathway
(also signaling cascade) chain of events that occurs in the cytoplasm of the cell to propagate the signal from the plasma membrane to produce a response
synaptic signal
chemical signal (neurotransmitter) that travels between nerve cells
target cell
cell that has a receptor for a signal or ligand from a signaling cell
anaphase
the stage of mitosis during which sister chromatids are separated from each other
binary fission
prokaryotic cell division process
cell cycle
ordered series of events involving cell growth and cell division that produces two new daughter cells
cell cycle checkpoint
mechanism that monitors the preparedness of a eukaryotic cell to advance through the various cell cycle stages
cell plate
a structure formed during plant-cell cytokinesis by Golgi vesicles fusing at the metaphase plate; will ultimately lead to formation of a cell wall to separate the two daughter cells
centriole
rod-like structure constructed of microtubules at the center of each animal cell centrosome
centromere
region at which sister chromatids are bound together; a constricted area in condensed chromosomes
chromatid
single DNA molecule of two strands of duplicated DNA and associated proteins held together at the centromere
cleavage furrow
constriction formed by an actin ring during cytokinesis in animal cells that leads to cytoplasmic division
condensin
proteins that help sister chromatids coil during prophase
cyclin
one of a group of proteins that act in conjunction with cyclin-dependent kinases to help regulate the cell cycle by phosphorylating key proteins; the concentrations of cyclins fluctuate throughout the cell cycle
cyclin-dependent kinase
one of a group of protein kinases that helps to regulate the cell cycle when bound to cyclin; it functions to phosphorylate other proteins that are either activated or inactivated by phosphorylation
cytokinesis
division of the cytoplasm following mitosis that forms two daughter cells.
diploid
cell, nucleus, or organism containing two sets of chromosomes (2n)
FtsZ
a tubulin-like protein component of the prokaryotic cytoskeleton that is important in prokaryotic cytokinesis (name origin: Filamenting temperature-sensitive mutant Z)
G0 phase
distinct from the G1 phase of interphase; a cell in G0 is not preparing to divide
G1 phase
(also, first gap) first phase of interphase centered on cell growth during mitosis
G2 phase
(also, second gap) third phase of interphase during which the cell undergoes final preparations for mitosis
gamete
haploid reproductive cell or sex cell (sperm, pollen grain, or egg)
gene
physical and functional unit of heredity, a sequence of DNA that codes for a protein
genome
total genetic information of a cell or organism
haploid
cell, nucleus, or organism containing one set of chromosomes (n)
histone
one of several similar, highly conserved, low molecular weight, basic proteins found in the chromatin of all eukaryotic cells; associates with DNA to form nucleosomes
homologous chromosomes
chromosomes of the same morphology with genes in the same location; diploid organisms have pairs of homologous chromosomes (homologs), with each homolog derived from a different parent
interphase
period of the cell cycle leading up to mitosis; includes G1, S, and G2 phases (the interim period between two consecutive cell divisions)
karyokinesis
mitotic nuclear division
kinetochore
protein structure associated with the centromere of each sister chromatid that attracts and binds spindle microtubules during prometaphase
locus
position of a gene on a chromosome
metaphase
stage of mitosis during which chromosomes are aligned at the metaphase plate
metaphase plate
the equatorial plane midway between two poles of a cell where the chromosomes align during metaphase
mitosis
(also, karyokinesis) period of the cell cycle during which the duplicated chromosomes are separated into identical nuclei; includes prophase, prometaphase, metaphase, anaphase, and telophase
mitotic phase
period of the cell cycle during which duplicated chromosomes are distributed into two nuclei and cytoplasmic contents are divided; includes karyokinesis (mitosis) and cytokinesis
mitotic spindle
apparatus composed of microtubules that orchestrates the movement of chromosomes during mitosis
nucleosome
subunit of chromatin composed of a short length of DNA wrapped around a core of histone proteins
oncogene
mutated version of a normal gene involved in the positive regulation of the cell cycle
origin
(also, ORI) region of the prokaryotic chromosome where replication begins (origin of replication)
p21
cell cycle regulatory protein that inhibits the cell cycle; its levels are controlled by p53
p53
cell cycle regulatory protein that regulates cell growth and monitors DNA damage; it halts the progression of the cell cycle in cases of DNA damage and may induce apoptosis
prometaphase
stage of mitosis during which the nuclear membrane breaks down and mitotic spindle fibers attach to kinetochores
prophase
stage of mitosis during which chromosomes condense and the mitotic spindle begins to form
proto-oncogene
normal gene that when mutated becomes an oncogene
quiescent
refers to a cell that is performing normal cell functions and has not initiated preparations for cell division
Retinoblastoma protein (Rb)
regulatory molecule that exhibits negative effects on the cell cycle by interacting with a transcription factor (E2F)
S phase
second, or synthesis, stage of interphase during which DNA replication occurs
septum
structure formed in a bacterial cell as a precursor to the separation of the cell into two daughter cells
telophase
stage of mitosis during which chromosomes arrive at opposite poles, decondense, and are surrounded by a new nuclear envelope
tumor suppressor gene
segment of DNA that codes for regulator proteins that prevent the cell from undergoing uncontrolled division
Note
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