Chapter 6

Question 1

plasma membrane

Answer 1

thin layer of lipids and proteins that separates the cell in its surroundings

Question 2

bilayer

Answer 2

layer two molecules thick

Question 3

cholesterol

Answer 3

predominant sterol in animal cells membranes

Question 4

transport proteins

Answer 4

form channels that allow selected polar molecules and ions to pass through membrane

Question 5

recognition proteins

Answer 5

identify a cell as part of the individual or foreign

Question 6

receptor proteins

Answer 6

bind cells close together by recognizing and binding receptors or chemical groups on other cells or the ecm

Question 7

glycolipids

Answer 7

lipid molecules with carbohydrate group attached

Question 8

glycoproteins

Answer 8

carbohydrates being attached to protein in exterior facing lipid layer

Question 9

glycocalyx

Answer 9

surface coat on cell membrane made of glycolipids and glycoproteins

Question 10

fluid mosaic model

Answer 10

membrane consists of fluid phospholipid bilayer where proteins are embedded and float freely

Question 11

integral proteins

Answer 11

proteins embedded in phospholipid layer

Question 12

peripheral protenis

Answer 12

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

Question 13

freeze fracture technique

Answer 13

freezing a group of cells and then breaking the frozen piece to see the inside

Question 14

transport

Answer 14

controlled movement of ions and molecules from one side of the membrane to another
passive-high to love
active-low to high

Question 15

difficusion

Answer 15

net movement from high conc to low conc

Question 16

concentration gradient

Answer 16

form of potential energy that drives diffusions

Question 17

selectively permeable

Answer 17

membranes that allow, impede, or block certain molecule and ions from crossing the membrane

Question 18

simple diffusion

Answer 18

depends solely on molecular size and lipid solubility

Question 19

facilitated diffusion

Answer 19

when proteins help polar and charged molecule cross membrane

Question 20

channel proteins

Answer 20

form hydrphobic channels in membrane that allow water and ions to pass

Question 21

aquaporins

Answer 21

allow water to pass through membrane

Question 22

gated channels

Answer 22

can switch between open, closed or intermediates

Question 23

carrier proteins

Answer 23

bind to a specific solute and transport it across membrane

Question 24

osmosis

Answer 24

passive transport of water

Question 25

osmotic pressure

Answer 25

pressure created by the weight of the water of the raised solution balancing the tendency of the water molecules moving in

Question 26

hypotonic

Answer 26

concentration of cell is higher than surroundings

Question 27

turgor pressure

Answer 27

pressure pushes cells tightly against their walls to support soft tissue against gravity

Question 28

hypertonic

Answer 28

concentration inside cell is lower than surroundings

Question 29

plasmolysis

Answer 29

plant cells shrink and retract cell walls

Question 30

isotonic

Answer 30

concentration inside and outside cell is equal

Question 31

membrane potential

Answer 31

active transport of ions may result in a voltage being generated across membrane

Question 32

primary active transport

Answer 32

protein that transports substance hydrolyzes atp to power itself

Question 33

secondary active transport

Answer 33

indirectly driven by atp hydrolysis

Question 34

h+ pump

Answer 34

moves hydrogen atoms across membrane temporarily binding to phosphate group removed from atp during cycle

Question 35

ca2+ pump

Answer 35

pushes calcium from cytoplasm to cell exterior and from cytosol to vesicles in er

Question 36

sodium potassium pump

Answer 36

pumps out 3 sodiums and brings in 2 pottasiums created a potential

Question 37

electrochemical gradient

Answer 37

electrical difference on two sides of membranes

Question 38

symport co transport

Answer 38

solute moves through membrane channel in same direction as driving ion

Question 39

antiport exchange diffusion

Answer 39

driving ion moves through membrane in one direction and another molecule moves in the other

Question 40

bulk phase endocytosis

Answer 40

cell takes in small drop of outside fluid and any molecules with it

Question 41

coated pit

Answer 41

depression in plasma membrane where receptor proteins go once bound to molecules

Question 42

clathrin

Answer 42

network of proteins that coat and reinforce cytoplasmic side

Question 43

phagocytosis

Answer 43

processes of a cell eating a molecule; engulf material and produce large endocytic vesicles