Chapter 4 - Membranes and Transport

Question 1

What are artificial membranes

Answer 1

simple mixtures of amphipathic lipid molecules that form structures to minimize potential energy

Question 2

what are the parts of a amphipathic molecule

Answer 2

polar at one end (try to interact with water) and non polar at the other (try not to interact with water)

Question 3

Where are the intrinsic proteins or transmembrane proteins embedded

Answer 3

lipid bilayer

Question 4

extrinsic proteins are

Answer 4

loosely associated with the membrane (can be attached to transmembrane proteins or with the lipids on one side

Question 5

a membrane with lots of saturated fatty acids

Answer 5

intact at higher temperatures and solid at low temperatures

Question 6

a membrane with lots of unsaturated fatty acids

Answer 6

fluid at lower temperatures and not able to function at higher temperatures

Question 7

Carbon double bonds induce “kinks” in fatty acid tails and

Answer 7

reduce surface area for interactions

Question 8

cholesterol disrupts

Answer 8

hydrophobic interactions in fatty acid tails

Question 9

transmembrane proteins aid in transport of

Answer 9

ions and polar molecules and signal communication

Question 10

what molecules can cross the phospholipid bilayer

Answer 10

non-polar and small uncharged polar

Question 11

what molecules cannot cross the phospholipid bilayer

Answer 11

large uncharged polar molecules and ions

Question 12

diffusion

Answer 12

high to low concentration

Question 13

osmosis

Answer 13

low concentration of solute to high concentration of solute

Question 14

water is ______ and cannot easily cross cell membrane

Answer 14

polar

Question 15

what is needed for water to cross membrane

Answer 15

aquaporin

Question 16

facilitated diffusion requires ______ to get molecules across membrane

Answer 16

proteins

Question 17

channel proteins form ______

Answer 17

openings in plasma membrane

Question 18

carrier proteins take molecules from

Answer 18

one side to the other

Question 19

hypotonic moves _____ cell

Answer 19

into

Question 20

hypertonic moves ______ cell

Answer 20

out of

Question 21

Symporters bind 2 solutes and moves them across the membrane in the ____ direction

Answer 21

same

Question 22

antiporters bind 2 solutes and move them in the ______ direction across the membrane

Answer 22

opposite

Question 23

Symporters and anti ports are often used for ______ transport

Answer 23

active

Question 24

active transport moves solutes from _____ to ______ concentrations using ATP as energy source

Answer 24

low to high

Question 25

primary active transport moves solute using ___ as energy source

Answer 25

ATP

Question 26

Secondary Active transport uses energy available due to a _______, favourable concentration gradient

Answer 26

second