Ch. 9 - Cell Interactions Flashcards
the process by which cells can detect, interpret, & respond to signals in their environment
Cell Communication
being able to respond to change at the cellular level
Cellular Response
enable cells to pass ions, signaling, molecules & other materials between the cytosol of one cell and the cytosol of the other
Direct Intercellular Signaling
molecules that are bound to the surface of a cell & provide a signal to other cells that make contact with the surface of the cell
Contact-Dependent Signaling
cell secretes signaling molecules that bind to receptors on its own cell surface & on the surfaces of neighboring cells of the same cell type; senses cell density
Autocrine Signaling
specific cell secretes a signaling molecule that does not affect that cell but instead influences the behavior of target cells in close proximity; short duration
Paracrine Signaling
excrete hormones into the bloodstream; long distances
Endocrine Signaling
molecules involved in long-distance signaling
Hormones
receptors found in the plasma membrane
Cell Surface Receptors
enzymes that transfer a phosphate group from ATP to a specific amino acid in a protein
Protein Kinases
seven transmembrane segments that wind back and forth through the plasma membrane; interact with G-proteins; bind GTP and GDP
G-Protein-Coupled Receptors
ion channels are proteins that allow the diffusion of ions across cell membranes; important in the transmission of signals between neurons & muscle cells & between two neurons
Ligand-Gated Ion Channels
extracellular signaling molecule must diffuse through the plasma membrane to gain access to its receptors; turns on the transcription of specific genes
Intracellular Receptor
category of enzyme-linked receptors that are found in all animals & also in choanoflagellates
Receptor Tyrosine Kinases
signaling molecule that promotes cell division
Growth Factor
phosphorylated form of the EGF receptor is first recognized by arelay protein of the signal transduction pathway called Grb; changes conformation of Grb & binds to another protein
Relay Proteins
the phenomenon in which one or more components of one signal transduction pathway affects a different signal transduction pathway
Crosstalk
programmed cell death
Apoptosis
activation of death receptors on the cell surface
Extrinsic Pathway
complex between the death receptors, adaptors, and initiator procaspase
Death-Inducing Signaling Complex
an active one functions as a protease
Caspase
an enzyme that digests other proteins
Protease
activated by initiator caspase & responsible for digesting intracellular proteins and causing them to die
Executioner Caspase
stimulated by DNA change that could cause cancer
Intrinsic Pathway
The interactions that do not involve direct contact between cells
Indirect Intercellular Attachments
The junctions between two cells in the epithelial membrane
Tight Junctions
A structure by which two adjacent cells are attached, formed from protein plaques in the cell membranes linked by filaments
Desmosomes
Multiprotein complexes that create the stable adhesion of basal epithelial cells to the underlying basement membrane
Hemidesmosomes
Aggregates of intercellular channels that permit direct cell-cell transfer of ions and small molecules
Gap Junctions
A narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells and allows communication between them
Plasmodesmata
