H2O & H2O Movement Flashcards
RG2
solvent
any LIQUID in which solid/gas will dissolve in
solute
SOLID/GAS dissolved in solute (liquid)
acid
e- donates → more protons present
- readily acquire protons when in contact w/ H2O
- conc. of H+ ions > OH- ions
(ie) HCl
base
e- accepts → less protons
- conc. of H+ ions > OH- ions
(ie) NaOH
diffusion
movement of molecules/ions from 1 region a otra
- often movement of high conc. to low conc. & vice versa
concentration gradient
difference across space (e.g., across a membrane) in the concentration of a dissolved substance
H2O properties
(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
osmosis
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.)
cohesion
attraction btwn LIKE molecules
- no cohesion = H2O vaporize
(ie) cause H2O to form rain droplets when falling
adhesion
attraction btwn UNLIKE molecules
(ie) causes meniscus
surface tension
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
pH
measurement of conc. of protons in solution (acidity or alkalinity)
pH= -log[H+]
pH significance to biological systems
(1) normal fcn of cell depend on maintaining neutral internal environment
(2) buffers help create homeostasis
(3) determines living from nonliving
buffer
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
hypertonic
HIGH outside conc, inside LOWER conc
- homeostasis: water leaves, vesicle shrinks, membrane shrivels = lower vesicle firmness
“lower tone”
hypotonic
LOW outside conc, inside solution HIGH conc.
- incoming water cause vesicle to swell -> increase firmness, or even burst
“excess tone”
isotonic
solute conc. equal on both sides of membrane
- liposomes maintains size
“equal tone”
specific heat
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
heat of vaporization
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
pH properties
(1) low = acid
(2) high = base
(3) large [H+] conc. = base
(4) small [H+] conc = acidic
importance of acids & bases
charge contributes to how molecules interact
(ie) regulation of gene translation
