ch 6

Question 1

Phosholipid

Answer 1

• bilayer
• amphipathic (hydrophilic head, hydrophobic tail)
• hydrophobic barrier: keeps hydrophilic molecules out

Question 2

Cell membrane

Answer 2

plasma membranes are selectively permeable

Question 3

selectively permeable

Answer 3

allow some substance to cross more easily than others
small molecules cross easily (hydrocarbons, co2 o2 )
hydrophobic cor prevents passage on ions, large polar molecules

Question 4

fluid mosaic model

Answer 4

FLUID: membrane held together by weak interactions
MOSAIC: phospholipids, proteins, carbs

Question 5

two kinds of membrane proteins

Answer 5

integral and peripheral

Question 6

integral proteins

Answer 6

embedded in membran
determined by freeze fracture
transmembrane with hydrophilic heads/tails and hydrophobic middles

Question 7

peripheral proteins

Answer 7

extracellular of membrane
not embedded
held in place by ecm
provides stronger framework

Question 8

functions of membrane proteins

Answer 8

transport
enzymatic activity 
signical transduction 
cell to cell recognition 
intercellular joining 
attachment to the cytoskeleton and ecm

Question 9

Passive transport

Answer 9

no energy needed
diffusion (down concentration gradient)
High to low concentration
e.g.. co2 o2 h2o

Question 10

carbohydrates functions

Answer 10

cell to cell recognition and developing organisms

Question 11

examples of carbs in cell membrane

Answer 11

glycolipids, glycoproteins

blood transfusion and type specific

Question 12

diffusion

Answer 12

spreading of something more widely

Question 13

what does diffusion do

Answer 13

reach equilibrium

Question 14

the freeze fracture method

Answer 14

revealed the structure of membranes interior

Question 15

how do cells arrange themselves in groups?

Answer 15

cell recognition
cell adhesion
(integral glycoproteins)

Question 16

fibers of ecm

Answer 16

collagen
fibronectin
proteoglycan complex

Question 17

cholesterol

Answer 17

helps with fluidity inside membrane

Question 18

carrier protein example

Answer 18

glucose transport protein

Question 19

osmosis

Answer 19

diffusion of water (high to low)

Question 20

active transport

Answer 20

requires energy (ATP)
proteins transport substances AGAINST concentration gradient
low to high
eg. sodium potassium pump, proton pump

Question 21

the potassium channel

Answer 21

custom fit for potassium

potassium is attracted by the negative oxygen atoms in protein

Question 22

hypertonic

Answer 22

high solute causes cells to shrivel

Question 23

isotonic

Answer 23

neutral

Question 24

hypotonic

Answer 24

low solute causing cells to swell

Question 25

three types of proteins for active transport

Answer 25

uniporter symporter antiporter

Question 26

uniporter

Answer 26

transports one substance in one directions

Question 27

symporter

Answer 27

transports two different substances in the same direction

Question 28

antiporter

Answer 28

transports two different substances in opposite direction

Question 29

aquaporin

Answer 29

channel protein that allows passage of water

Question 30

facilitated diffusion

Answer 30

``` requires transport proteins help hydrophilic substances cross two ways: provide hydrophilic channel loosely bind/carry molecule across eg. water, glucose ions polar molecules ```

Question 31

what are transport proteins

Answer 31

channel or carrier proteins

Question 32

electronic pumps

Answer 32

generate voltage across membranes | eg. sodium potassium and proton pump

Question 33

sodium potassium pump

Answer 33

pumps sodium out and potassium into cell | nerve transmission

Question 34

proton pump

Answer 34

``` pushes protons (H+) across membrane ex. mitochondria (ATP production) ```

Question 35

cotransport

Answer 35

membrane protein enables "downhill" diffusion of one solute to drive "uphill" transport of other eg. atp production in plants

Question 36

Passive transport

Answer 36

little to no energy high to low concentrations down the concentration gradient eg. diffusion, osmosis, facilitated diffusion (w/ transport protein)

Question 37

active transport

Answer 37

requires energy (ATP) low to high concentration against concentration gradient eg. pumps, exo/endocytosis

Question 38

bulk transport

Answer 38

transport of proteins, polysaccharides, large molecules eg. endocytosis exocytosis

Question 39

endocytosis

Answer 39

take in molecules, form new vesicles

Question 40

exocytosis

Answer 40

vesicles fuse with cell membrane, expel contents

Question 41

types of endocytosis

Answer 41

phagocytosis | pinocytosis

Question 42

phagocytosis

Answer 42

cellular eating - solids

Question 43

pinocytosis

Answer 43

cellular drinking - fluids

Question 44

receptor mediated endocytosis;

Answer 44

ligands bind to specific receptor on cell surface

Question 45

osmoregulation

Answer 45

control solute and water balance contractile vacuole eg. paramecium caudatum - freshwater protist

Question 46

contractile vacuole

Answer 46

bilge pump, forces out fresh water as it enter by osmosis