chapter 3 (study guide and powerpoint)

define osmolarity

define osmolarity

total concentration of all solute particles in a solution

what is osmolarity expressed as

osmoses per liter

hyposmotic means a … OsM

lower

hyperosmotic means a … OsM

higher

isosmotic means … OsM

equal

define osmotic pressure

force associated with osmosis, occurs when solutions of different OsM are separated by a semi-permeable membrane

define a hypotonic environment

GAIN water via osmosis and may burst (lysis) due to HIGH osmotic pressure

define a hypertonic environment

LOSE water via osmosis and shrink (crenation) due to LOW osmotic pressure

what is the calculation for pH

-log [concentration of H+]

the pH of pure water … as temperature INCREASES

DECREASES

acids … [H+] and thus DECREASES pH

increases

bases … [H+] and thus INCREASES pH

decreases

define a buffer

diminishes effects of acids and bases on pH change, work only over a particular pH range

pK is pH at which…

half an acid dissociates

what does pK value reflects…

strength of acids and bases

pK less than 3 means a …. acid

strong

pK greater than 11 means a … base

strong

2 changes in pH and temperature

• affect ionization of amino acids

• affect protein structure and function

name 2 important buffers in cytoplasm (intracellular)

phosphate and histadine

name an important buffer in extracellular fluids

bicarbonate

why is it important for animals to maintain pH homeostasis? what effect does pH change have on amino acids and protein structure/function)?

CO2 reacts with water to produce carbonic acid → Carbonic acid H2CO3 dissociates to release H+ and bicarbonate ions HCO3- → CO2 + H2O →  H2CO3 → H+ + HCO3- → Changes in Co2 level and pH determines net reaction to “left” and “right” → Bicarbonate buffer system resists changes in blood pH. → Normal blood pH is about 7.4 (slightly basic). → If blood pH rises (becomes too basic), then more carbonic acid dissociates  releasing more H+. →If blood pH falls (becomes too acidic), then more bicarbonate ions bind with H+.

what are the other 4 types of bonds

hydrogen bonds

van der Waals forces

ionic bonds

hydrophobic interactions

low temperature … attractive (Van der Waals) force between lipids

strengthens

what do animals add to their membrane which allows them to remodel at lower temperature

cholesterol

define passive diffusion

movement across the concentration gradient directly across the membrane (high → low), no energy or channels needed

define facilitated diffusion

requires the use of ion channels (permease or aquaporins)

define primary active transport

requires ATP

for example, Na+/ K+ pump

define secondary active transport

requires ATP

for example, exchanger (anti porter) or co-transporter (symport)

how are lipids stored

triglycerides

easily stored

how are carbohydrates stored

glycogen granules

lipids are metabolized … than carbohydrates are

SLOWER

lipids have a … energy content per unit mass

HIGH

carbohydrates are metabolized … than lipids are

FASTER

carbohydrates have a … ratio of ATP produced/ o2 consumed

HIGHER

define the respiratory quotient (RQ)

ratio between CO2 formed in metabolism and O2 used

what is the formula for RQ

CO2 formed / O2 used 

what is the RQ for carbohydrate

1.0

what is the RQ for fat

0.7

what is the RQ for protein

0.8

what are receptors, ion channels and carriers made up of

proteins