Definitions Flashcards
resolving power/limit of resolution
the ability of a microscope to distinguish adjacent objects as separate entities
tranmission electron microscopy (TEM)
type of electron microscope in which an image is formed by electrons that are transmitted through a specimen
chromatography
the separation of a mixture by passing it in solution or suspension or as a vapor (as in gas chromatography) through a medium in which the components move at different rates.
nucleic acid hybridization
A technique in which single-stranded nucleic acids (DNA or RNA) are allowed to interact so that complexes called hybrids are formed by molecules with similar, complementary sequences
in vitro
(of a process) performed or taking place in a test tube, culture dish, or elsewhere outside a living organism.
sterols
any of numerous compounds consisting of a 17-carbon 4 ring system with at least one hydroxyl group and a variety of other possible side groups
cadherins
extracellular sequences of amino acids that bind to calcium and promote adhesion between similar types of cells in a tissue
lipid anchored proteins
protein located on a membrane surface that is covalently bound to one or more lipid molecules residing within the lipid bilayer
sphingolipids
class of lipids containing the amine alcohol shpingosine as a backbone
lipid rafts
localized region on membrane lipids, often charaterized by elevated levels of cholesterol or glycosphingolipids, that sequester proteins involved in cell signaling
fluorescent antibodies
antibody containing covalently linked fluorescent dye molecules that allow the antibody to be used to locate antigen molecules microscopically
electrochemical potential
transmembrane gradient of an ion, with both an electrivcal component due to the charge separation quantified by the membrane potential and a concentration component; also called electrochemical potential
alternating conformation model
membrane transport model in which a carrier protein alternates between two conformational states, such that the solute binding site of the protein is open or accessible first to one side of the membrane and then to the other
symport/symporter
coupled transport of two solutes across a membrane in the same direction
bacteriorhodopsin
transmembrane protein complexed with rhodopsin, capable of transporting protons across the bacterial cell membrane to create a light dependent electrochemical proton gradient
selectins
plasma membrane glycoprotein that mediates cell-cell adhesion by binding to specific carbohydrate groups located on the surface of target cells
proteoglycans
complex between proteins and glycosaminoglycans found in the extracellular matrix
integrins
any of several plasma membrane receptors that bind to extracellular matrix components at the outer membrane surface and interact with cytoskeleton components at the inner membrane surface; includes receptors for fibronectin, laminin, and collagen
plasmodesmata
cytoplasmic channel through pores in the cell walls of two adjacent plant cells, allowing fusion of the plasma membrane and chemical communication between cells
transitional elements
region of the ER that is involved in the formation of transition vesicles
phospholipid exchange proteins
any of a group of proteins located in the cytosol that transfer specific phosphlipid molecules from the ER membrane to the outer mitochondrial, chloroplast, or plasma membrane
terminal glycosylations
modification of glycoproteins in the golgi complex involving removal and/or addition of sugars to the carbohydrate side chains formed by prior core glycosylation in the ER
glyoxysomes
specialized type of plant peroxisome that contains some of the enzymes responsible for the conversion of stored fat to carbohydrate in germinating seeds
fluid phase endocytosis
non specific uptake of extracellular fluid by infolding of the plasma membrane, followed by budding off of a membrane vesicle
