chapter seven

Question 1

phospholipid bilayer

Answer 1

polar hydrophilic heads
nonpolar hydrophobic tails

Question 2

fluid nature

Answer 2

all of the pieces can move around, phospholipid and protein movement

Question 3

cholesterol: moderate temp

Answer 3

decreases fluidity

Question 4

cholesterol: low temp

Answer 4

increases fluidity

Question 5

membrane proteins

Answer 5

complete the mosaic

Question 6

integral proteins

Answer 6

embedded in, surface shown on each side of cell, held to internal surface by cytoskeleton

Question 7

peripheral proteins

Answer 7

only on either side, held to external surface by extra cellular matrix (ECM)

Question 8

six major protein functions

Answer 8

transport
enzymatic activity
signal transduction
cell to cell recognition
intercellular joining
attachment to cytoskeleton

Question 9

membrane carbohydrates

Answer 9

allow cell to cell recognition, important in development and immunology

Question 10

selective permeability

Answer 10

selective on which molecules and/or ions can past through the bilayer

Question 11

bilayer permeability

Answer 11

nonpolar molecules (hormones, CO2, O2) can pass
polar molecules (glucose, H2O) blocked by nonpolar tails
ions (H+, Ca2+) also blocked

Question 12

transport proteins

Answer 12

nonpolar molecules blocked
polar molecules can pass
ions can pass

Question 13

hydrophilic tunnel

Answer 13

safe passage through hydrophobic phospholipid tails

Question 14

aquaporins

Answer 14

water pores

Question 15

specificity

Answer 15

each protein only works with a specific molecule

Question 16

passive transport

Answer 16

goes with the concentration gradient, no energy needed

Question 17

concentration gradients

Answer 17

the amount of particles on one side compared to the other

Question 18

osmosis

Answer 18

the diffusion of water

Question 19

hypertonic

Answer 19

higher concentration of solute

Question 20

hypotonic

Answer 20

lower concentration of solute

Question 21

osmoregulation

Answer 21

osmosis cant be stopped, organisms have to evolve ways to deal with it

Question 22

turgid

Answer 22

very firm, healthy state for plants

Question 23

flaccid

Answer 23

limp and wilted

Question 24

plasmolysis

Answer 24

plasma membrane pulls away from the cell wall, shriveled

Question 25

facilitated diffusion

Answer 25

many polar molecules and ions blocked by the lipid bilayer of the membrane diffuse passively

Question 26

active transport

Answer 26

goes against the gradient, molecules flow from low to high, uses pumps

Question 27

NaK pump

Answer 27

Na out, K in, has charges so can’t just flow through membrane

Question 28

ion pumps

Answer 28

creates membrane potential between -50 and -200mV

Question 29

electrogenic pumps

Answer 29

create potential energy

Question 30

cotransport

Answer 30

H+ wants to go in but cell wants it out so it brings sucrose in with the H+

Question 31

exo(exit)/endo(bring in) cytosis

Answer 31

no gradient but uses energy

Question 32

phagocytosis

Answer 32

white blood cell, food

Question 33

pinocytosis

Answer 33

large fluid/liquid