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As size of organismincreases SA volratio decreases
Large organisms need specialisedsystemsto obtainrequired substances
Dueto large diffusion pathway
SA Vol volumemust be I div bothsides byvolume
volume of sphere I Tir I differentiate
SH of sphere yare
metabolic rate theamount of energyexpended by an organism in a giventime
pergramoftissue anowscomparisonbetweendifferentorganisms
as overansizesdiffer
smallorganisms have a high metabolic rate per gramtissue
larger SA voiratio
more heatloss
theyrespiremore to maintain heat
measuring metabolic rate
Oz uptake coz loss asused in respirationwhich is a metabolic processthatprovidesATP
, for alveoli
Forsingle celledgas exchange need 3 components of Fick's Law
rate of diffusion a surface area x conegradient
diffusionpathwaylength
Insect gas exchange
thinvacuolewalls shortdiffpathway
trachaeprovidetubesfunofair concgrad fastdiffusion
fluidmovesfromendoftrackour muscle aus in exercise
fasterdiffusionin airthanwater
At rest
Oz used in aerobicrespso low conc in muscle cell
maintains Or concgradientbetweentracheae high and muscle cell low
Or dissolver in fluid at endof tracheae and diffusesintomuscle
down conegradient
LightExercise
muscles around Wacheoles contract
volume of tracheoler I pressure t
coz moves out down pressure gradient
now lowpressure air moves in downpressure gradient
Intense exercise
anaerobicrespoccurs in musclecells whichproduces lactate
this decreases up of musclecell watermovesfromtracheal fluidto muscle cellsbyosmosisdow
up gradient
Oznowdoesntneedto dissolvein trachealfluid so gasexchangeoccurs in air which isquiche
thaninliquid so Oz diffusestomusclecells faster
, Fish gas exchange
gill arch
gillfilament
r
f Lamellate
con
water
Ign
Yggoomercurrent
How
mechanism
mouthopens opercularvalve shuts floor of mouthlowers
volume in pressure t water moves in downpressuregradient
mouthshuts operator valveopens floorofmouthraises
volume t pressure t waterpushedovergills
Adaptations
Gill filaments are long so can fitmanylamellae higher sit fordiffusion
Lamenal one cell thick shortdiffusionpathwayfor Oz and coz Jfaster diffusion
alsoforcoz T COUNTERCURRENT flow
water and blood flow in opposite directions
bloodalways passeswater with a higherOc conc
this maintains on concgradient
along wholelamella
mon or diffusesintoblood for AR
circulationreplacesbloodsaturated withOz
ventilation replaces waterwith no Or left
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