'/
Cellsdt Wo*-Photosynthesisand Respl.ation
tea,nirytwtrcetts
an
e[s AtWork-Photosynthesis
Obtalningand UslngEnergY
when som€oneasks,"wheredo Youg(
necessaryfor life This allows
all the activities
The sum totalof all your
ed fromons another.
remicalreactionsneedenzymes.An enzyme
ngesbythe breakingdownand joiningof mol'
a;ions in c€llscannottakeplace.Becauseot
Diration,thesun'senelgyis used.Photosyn'
r.Cellularresplratlonis the energy-releasing
to
this sugar'making
rlltogethetto understand
proc€ss.
sugar-burning
lot haveto eat Theyuse their leavesas lood
ressthatusessunlight.The food madeby the
lnge glucoseinto nutrients (starch,fats,and
I dioxide,in thepresenceof sunlight,are used
€ the rawmalerialsusedto producethe food'
ril, and veinscarrythe waterup and into the
catledstomata.Sunlightthenprory openings
e fi€ rawmatelialsintoglucose,a productthe
luceorygenandwater,whichis thengivenott
)lantscapturetheenergyin sunlightand useit
r thatis usedforthe plant'slifeprocesses'Th€
o eat-fruitsandvegetables
is a green
rophyll(KLORuh fil). Chloroptryll
ars mostlyfoundin the plant's
s. ChloroDlasts
can onlyoccur
Photosynthesis
foodfactories.
hesisreleasesmoreorygen lhan the planl
intotheair.Youuse lhe oxygen
sn is released
to breathsforyoutowncellularrespiration'
Atlplantsrsspirejust as we do'
needoxygen.
the planttakesin lhg
Jr methodof respiration;
occuG
Theother,cellularrespiration,
dioxids.
nutd€nts
down
lon is theprocessof breaking
occursin all cells in all organs-When
to createenergyfor cell processesThis breakdoran
Youinhaleoryqen
suchas carbondioxideareproduced
wastes,
oi"uf ao*" nukients'
""i[
il
I
ij
r
LearningAboutCells
Cellsal Work-Photosynthesis
and Resokation
and exhalecarbondioxide.Haveyou everbreathedon a mirrorbefore?Didyou see a fog on
the glass?Thefog is actuallywatervaporyou exhaledalongwiththe carbondioxide_
Duiing
chemicalreactions(changes)occurthat breakdownfoodmoleculesinto simple;
respiration,
substancesand releasestoredenergy.Just as withphotosynthesis,
enzymesare neededlor
the chemicalreactionsto takeplace.
Whathappenswhenyou run-do you beginto breathefasterand feelhot?Why does
this happen?It'sbecauseyourmusclecellsusea lotol energywhenyourun.Togettheneeded
energy,yourmusclecellsbreakdownfood.Yourmusclesusesomeof the energycrealedfrom
of yourfoodas you move.Someof theenergybecomesthermalenergy,which
the breakdown
is why you feelhot.i/ost cells needorygenin orderlo breakdownthe food;this is why you
breatheso fast.Yourmusclecellsneedand usethe oxygenfor the processof respiration.
In
chemicalreactionsoccurthal breakdownloodmoleculesintoa simplersubstance
respiration,
and releasestoredenergy.Reviewthe chemicalequationfor photosynthesis
and respiration,
make
a
comparison
of
the
Then
two equations.
PHOTOSYNTHESIS
(Heactants)
(Products)
6CO, + 6H,O + Sunlight --+
c^H,^o60,
Water
Carbon
Glucose
Oxygen
Dioxide
(Sugar)
RESPIRATION
(Feactants)
c6H,'o6
Sugar
+
60,
(Products)
'+
6CO,
Carbon
Dioxide
Oxygen
f
6HrO
Water
+
Energy
The ChemistryBehindlt All
Compounds
are represented
by a chemicalformula_Formulasshowhow manvand
what typeof atomsare foundin one moleculeol the compound.The smallnumbers,sub_
scripts,showhowmanyatomsof eachelementit takesto makethe compound.Forexample,
lherc ate 24 atomsin one moleculeof sugar.lt takes6 carbon,12 hydrogen,and 6 oxygen
atomsto makeone moleculeof sugar.The larg€numbersin frontof the comDound
formula.
indicatehowmanymolecules
coetlicienls,
of eachcompoundareneeded,
Sunlightand plaol and
cell struclurefor photosynthesig
i9 lvia* r-warnMedia lnc PlDIisheE
Planland anlmaland
cell structuretor reg9lration
38
tt,.
LBarning
AboutCells
Cellsat Work-Photosynlhesis
and Respiration
Date:
r'
.tl
To lhe studentobserveriExplainwhya plantdoesnot haveto eat.
Analyze:Compare
theprocessof respirution
to photosynthesis.
Partl. Direclions:Complete
the following.
1. Theloodthatplanlsmakeis
2. Thematerials
a plantusesto makesugarare
and
3. Photosynthesis
occursin cellsthatcontain
A chemical
formulashowsthe kindand numberof atomslhatlorma_
5. Organiccompounds
containthe element
o.
Planlsuse
energyfromthesunto makeglucose.
7. Metabolism
is thetotalof all
in an organism.
8.
occursin the mitochondria
in all cells.
9.
speedup chemicalchanges.
10. Chemical
reactions
takeplacein
solutions.
Partll. oirections:write"P"if it desdibesphotosynthesis
or'R" if it describesrespiration.
1. Carbondioxideis waste.
2. Occursin thechloroplasts
of plantcels
3. Orygenis givenoff.
4. Energyis stored,
5. Energyis burnedor released.
6 Occurs
in themitochondria
of allcells
i , r i l . q: 2 a r M . J ? . 1 . . F . i i s i a r s
i9