H2O & H2O Movement

Question 1

solvent

Answer 1

any LIQUID in which solid/gas will dissolve in

Question 2

solute

Answer 2

SOLID/GAS dissolved in solute (liquid)

Question 3

acid

Answer 3

e- donates → more protons present

• readily acquire protons when in contact w/ H2O
• conc. of H+ ions > OH- ions

(ie) HCl

Question 4

base

Answer 4

e- accepts → less protons
- conc. of H+ ions > OH- ions

(ie) NaOH

Question 5

diffusion

Answer 5

movement of molecules/ions from 1 region a otra

- often movement of high conc. to low conc. & vice versa

Question 6

concentration gradient

Answer 6

difference across space (e.g., across a membrane) in the concentration of a dissolved substance

Question 7

H2O properties

Answer 7

(1) high electronegativity
(2) high surface tension
(3) high specific heat
(4) high capacity to store energy
(5) neutral pH of 7
(6) can be weak acid or weak base
(7) H-bonds (strongest IM force)
(8) H-bonds make possible for almost any charged or polar molecule to dissolve in H2O
(9) polar
(10) denser solid form than liquid form
(11) bent molecule

Question 8

osmosis

Answer 8

diffusion of H2O across a selectively permeable membrane from a region of low solute conc. (high H2O conc.) to region of high solute conc. (low H2O conc.)

Question 9

cohesion

Answer 9

attraction btwn LIKE molecules
- no cohesion = H2O vaporize

(ie) cause H2O to form rain droplets when falling

Question 10

adhesion

Answer 10

attraction btwn UNLIKE molecules

(ie) causes meniscus

Question 11

surface tension

Answer 11

cohesive force causing molecules @ liquid surface to stick juntos & resist deformation of liquid’s surface, thus minimize its surface area

(ie) how insects can walk on H2O

Question 12

pH

Answer 12

measurement of conc. of protons in solution (acidity or alkalinity)

pH= -log[H+]

Question 13

pH significance to biological systems

Answer 13

(1) normal fcn of cell depend on maintaining neutral internal environment
(2) buffers help create homeostasis
(3) determines living from nonliving

Question 14

buffer

Answer 14

compounds that minimize pH changes

• reduce impact of adding acids/bases in overall pH of solution
• most buffers = weak acids
• resist [H+] change in conc.

(ie) phosphate & proteins

Question 15

hypertonic

Answer 15

HIGH outside conc, inside LOWER conc
- homeostasis: water leaves, vesicle shrinks, membrane shrivels = lower vesicle firmness

“lower tone”

Question 16

hypotonic

Answer 16

LOW outside conc, inside solution HIGH conc.
- incoming water cause vesicle to swell -> increase firmness, or even burst

“excess tone”

Question 17

isotonic

Answer 17

solute conc. equal on both sides of membrane
- liposomes maintains size

“equal tone”

Question 18

specific heat

Answer 18

energy needed to ∆T

• neg. energy to ↑↓ 1gm of X 1˚C
• break H-bonds b4 rate of movement change

(ie) help maintain body homeostasis, esp. during exercise

Question 19

heat of vaporization

Answer 19

when H-bonds break & take off

• energy need to change phase
• neg. energy to change 1gm of X 1˚C

(ie) heat lost via perspiration

Question 20

pH properties

Answer 20

(1) low = acid
(2) high = base
(3) large [H+] conc. = base
(4) small [H+] conc = acidic

Question 21

importance of acids & bases

Answer 21

charge contributes to how molecules interact

(ie) regulation of gene translation