Definitions

Question 1

resolving power/limit of resolution

Answer 1

the ability of a microscope to distinguish adjacent objects as separate entities

Question 2

tranmission electron microscopy (TEM)

Answer 2

type of electron microscope in which an image is formed by electrons that are transmitted through a specimen

Question 3

chromatography

Answer 3

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.

Question 4

nucleic acid hybridization

Answer 4

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

Question 5

in vitro

Answer 5

(of a process) performed or taking place in a test tube, culture dish, or elsewhere outside a living organism.

Question 6

sterols

Answer 6

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

Question 7

cadherins

Answer 7

extracellular sequences of amino acids that bind to calcium and promote adhesion between similar types of cells in a tissue

Question 8

lipid anchored proteins

Answer 8

protein located on a membrane surface that is covalently bound to one or more lipid molecules residing within the lipid bilayer

Question 9

sphingolipids

Answer 9

class of lipids containing the amine alcohol shpingosine as a backbone

Question 10

lipid rafts

Answer 10

localized region on membrane lipids, often charaterized by elevated levels of cholesterol or glycosphingolipids, that sequester proteins involved in cell signaling

Question 11

fluorescent antibodies

Answer 11

antibody containing covalently linked fluorescent dye molecules that allow the antibody to be used to locate antigen molecules microscopically

Question 12

electrochemical potential

Answer 12

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

Question 13

alternating conformation model

Answer 13

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

Question 14

symport/symporter

Answer 14

coupled transport of two solutes across a membrane in the same direction

Question 15

bacteriorhodopsin

Answer 15

transmembrane protein complexed with rhodopsin, capable of transporting protons across the bacterial cell membrane to create a light dependent electrochemical proton gradient

Question 16

selectins

Answer 16

plasma membrane glycoprotein that mediates cell-cell adhesion by binding to specific carbohydrate groups located on the surface of target cells

Question 17

proteoglycans

Answer 17

complex between proteins and glycosaminoglycans found in the extracellular matrix

Question 18

integrins

Answer 18

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

Question 19

plasmodesmata

Answer 19

cytoplasmic channel through pores in the cell walls of two adjacent plant cells, allowing fusion of the plasma membrane and chemical communication between cells

Question 20

transitional elements

Answer 20

region of the ER that is involved in the formation of transition vesicles

Question 21

phospholipid exchange proteins

Answer 21

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

Question 22

terminal glycosylations

Answer 22

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

Question 23

glyoxysomes

Answer 23

specialized type of plant peroxisome that contains some of the enzymes responsible for the conversion of stored fat to carbohydrate in germinating seeds

Question 24

fluid phase endocytosis

Answer 24

non specific uptake of extracellular fluid by infolding of the plasma membrane, followed by budding off of a membrane vesicle