chapter 8 part 2; 8.6 osmosis and dialysis

Question 1

in a cell is the outer or inner membrane more permeable

Answer 1

outer

Question 2

is the inner member soluble

Answer 2

no;
water and certain solutes

Question 3

what are cell membranes composed of

Answer 3

phospholipids

Question 4

how many membranes does the nucleus have

Answer 4

two; that separate the DNA from the rest of the cell

Question 5

how many membranes does mitochondria have

Answer 5

two; separating the inner part from the cell’s cytosol

Question 6

since the inner membrane is not really soluble, how are things supposed to cross the membrane

Answer 6

proteins passes

Question 7

is the top of a phospholipid polar or nonpolar, hydrophobic or hydrophilic, and faced on the outside or inside

Answer 7

polar + hydrophilic
and face on the outside

Question 8

is the ends of a phospholipid polar or nonpolar, hydrophobic or hydrophilic, and faced on the outside or inside

Answer 8

nonpolar
hydrophobic
faced on the inside

Question 9

do kidneys also have selectively permeable membranes

Answer 9

yes; filter out waste from out bloodstream

Question 10

can colloids (large particles suspended in the solvent) and larger particles cross a selectively permeable membrane

Answer 10

no; have to have another way of crossing

Question 11

what is diffusion

Answer 11

• random movement of solute particles through the solvent
• results in uniform concentration of the solute
• two solutions of different concentration separated by a selectively permeable membrane is a concentration gradient

Question 12

two solutions of different concentration separated by a selectively permeable membrane creates a

Answer 12

concentration gradient

Question 13

are concentration gradients present in cells

Answer 13

yes

Question 14

what can make a gradient of concentration in a cell

Answer 14

certain ions present in higher concentrations outside of the cell compared to inside
e.g. sodium higher outside
e.g. potassium is higher inside

Question 14

what are permeable substances that are able to readily diffuse

Answer 14

small non polar molecules
e.g. O2, N2, CO2
small polar molecules
e.g. H2O

Question 15

what are permeable substances that need assistance (and sometimes energy)

Answer 15

larger polar molecules
e.g. C6H12O6
small monoatomic ions
e.g. Cl-. Na+. K+

Question 16

what are the three factors that determine the diffusion across a semi permeable membrane

Answer 16

size (smaller size)
charge (neutral solutes)
polarity (polar molecules have a more difficult time than nonpolar)
side note; molecules with charges have a difficult time crossing

Question 17

what are less permeable substances that are the least permeable

Answer 17

large polyatomic ion
e.g. phosphate
colloids

Question 18

what are less permeable substances that impermeable

Answer 18

proteins, polysaccharides (need to be broken down before being transported)
fats (large fat)

Question 19

substances with a […] size, […] charge and which are […] polar are better able to cross the cell membrance

Answer 19

smaller
neutral
less

Question 20

what is the inside and outside concentration (mM) of the electrolyte Na+

Answer 20

inside - 10 mM
outside - 140 mM
extra cellular electrolytes

Question 21

what is the middle and outside concentration (mM) of electrolyte Cl-

Answer 21

inside - 4 mM
outside - 100 mM
extra cellular electrolyte

Question 22

what is the middle and outside concentration (mM) of electrolyte K+

Answer 22

inside - 140 mM
outside - 4 mM
intracellular electrolyte

Question 23

what is the middle and outside concentration (mM) of electrolyte Ca charge 2+

Answer 23

inside - 1x10^-14 mM
outside - 2.5 mM
intracellular electrolyte