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Flashcards in Chapter 6 Deck (49):
1

a membrane with 2 molecular layers

bilayer

2

the predominant sterol of animal cell membranes

cholesterol

3

a protein embedded in the cell membrane that forms a channel allowing selected polar molecules and ions to pass across the membrane

transport proteins

4

protein in the plasma membrane that identifies a cell as part of the same individual or as foreign

recognition proteins

5

protein that recognizes and binds molecules from other cells that act as chemical signals

receptor proteins

6

protein that binds cells together by recognizing and binding receptors or chemical groups on other cells or on the extracellular matrix

cell adhesion proteins

7

a lipid molecule with carbohydrate groups attached

glycolipids

8

protein with carbohydrate groups attached

glycoproteins

9

a carbohydrate coat covering the cell surface

glycocalyx

10

model proposing that the membrane consists of a fluid phospholipid bilayer in which proteins are embedded and float freely

fluid mosaic model

11

protein embedded in a phospholipid bilayer

integral proteins

12

protein held to membrane surfaces by noncovalent bonds formed with the polar parts of integral membrane proteins or membrane lipids

peripheral proteins

13

technique in which experimenters freeze a block of cells rapidly, then fracture the block to split the lipid bilayer and expose the hydrophobic membrane interior

freeze-fracture technique

14

the controlled movement of ions and molecules from one side of a membrane to the other

transport

15

the transport of substances across cell membranes without expenditure of energy, as in diffusion

passive transport

16

the mechanisms by which ions and molecules move against the concentration gradient across a membrane from the side with the lower concentration to the side with the higher concentration

active transport

17

the net movement of ions or molecules from a region of higher concentration to a region of lower concentration

diffusion

18

a difference in concentration molecules or ions between 2 areas

concentration gradient

19

membranes that selectively allow, impede, or block the passage of atoms and molecules

selectively permeable

20

mechanism by which certain small substances diffuse through the lipid part of a biological membrane

simple diffusion

21

mechanism by which polar and charged molecules diffuse across membranes with the help of transport proteins

facilitated diffusion

22

transport protein that forms a hydrophilic channel in a cell membrane through which water, ions, or other molecules can pass, depending on the protein

channel proteins

23

a specialized protein channel that facilitates diffusion of water through cell membranes

aquaporins

24

ion transporter in a membrane that switches between open, closed, or intermediate states

gated channels

25

transport protein that binds a specific single solute and transports it across the lipid bilayer

carrier proteins

26

the passive transport of water across a selectively permeable membrane in response to solute concentration gradients, a pressure gradient, or both

osmosis

27

a state of dynamic equilibrium in which the pressure of the solution on one side of a selectively permeable membrane exactly balances the tendency of water molecules to diffuse passively from the other side of the membrane due to a concentration gradient

osmotic pressure

28

the effect a solution has on a cell when the solution surrounds it

tonicity

29

solution containing dissolved substances at lower concentrations than the cells it surrounds

hypotonic

30

the internal hydrostatic pressure within plant cells

turgor pressure

31

solution containing dissolved substances at higher concentrations than the cells it surrounds

hypertonic

32

conditions due to outward osmotic movement of water, in which plant cells shrink so much that they retract from their water

plasmolysis

33

equal concentration of water inside and outside cells

isotonic

34

the mechanism by which ions and molecules move against the concentration gradient across a membrane, from the side with the lower concentration to the side with the higher concentration

active transport

35

an electrical voltage that measures the potential inside a cell membrane relative to the fluid just outside; it is negative under resting conditions and becomes positive during an action potential

membrane potential

36

transport in which the same protein that transports a substance also hydrolyzes ATP to power the transport directly

primary active transport

37

transport indirectly driven by ATP hydrolysis

secondary active transport

38

pump that moves hydrogen ions across membrane and pushes hydrogen ions across the plasma membrane from the cytoplasm to the cell exterior

proton pumps/ H+ pump

39

pump that pushes Ca2+ from the cytoplasm to the cell exterior, and also from the cytosol into the vesicles of the endoplasmic

Ca2+ pump

40

pump that pushes 3 Na+ out of the cell and 2 K+ into the cell in the same pumping cycle

Na+/K+ pump

41

a difference in chemical concentration and electric potential across a membrane

electrochemical gradient

42

the transport of 2 molecules in the same direction across a membrane

symport

43

a secondary active transport mechanism in which a molecule moves through a membrane channel into a cell and powers the active transport of a second molecule out of the cell

antiport/exchange diffusion

44

mechanism by which extracellular water is taken into a cell together with any molecules that happen to be in solution in the water

bulk-phase endocytosis

45

the selective uptake of macromolecules that bind to cell surface receptors concentrated in clathrin-coated pits

receptor-mediated endocytosis

46

a depression in the plasma membrane that contains receptors for macromolecules to be taken up by endocytosis

coated pit

47

the network of proteins that coat and reinforce the cytoplamic surface of cell membranes

clathrin

48

process in which some types of cells engulf bacteria or other cellular debris to break them down

phagocytosis

49

the outer limit of the cytoplasm responsible for the regulation of substances moving into and out of cells

plasma membrane